Acoustic structure and related electronic device

Abstract

Various embodiments of the present disclosure relate to an acoustic structure and a related electronic device. The acoustic structure comprises: an acoustic waveguide network having a main acoustic inlet and a main acoustic outlet; and at least one acoustic resonator arranged to be in communication with the interior of the acoustic waveguide network via an opening in a side wall of the acoustic waveguide network. The acoustic structure is adapted to receive sound via the main acoustic inlet, and after the sound is processed by the acoustic waveguide network and the at least one acoustic resonator, to output the processed sound via the main acoustic outlet.

Description

Acoustic structures and related electronic devices

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 756,254, filed February 9, 2025, entitled “Phone Case with Built-in Metamaterial Equalizer,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of acoustic engineering, and more specifically to an acoustic structure and related electronic equipment. Background Technology

[0004] Electronic devices typically have speakers for sound output. However, as devices become smaller, especially in compact devices such as portable electronic devices, providing high-quality sound output can be challenging.

[0005] Acoustic metamaterial equalizers are a new type of passive filter designed based on acoustic metamaterials. They utilize artificially designed microstructures instead of traditional electronic circuits to achieve precise control of sound frequency response.

[0006] There is currently a need to apply acoustic metamaterial equalizers to electronic devices to improve the sound output quality of speakers. Summary of the Invention

[0007] The purpose of this disclosure is to propose a novel acoustic structure and related electronic devices that can effectively improve the sound quality of electronic devices.

[0008] According to a first aspect of this disclosure, an acoustic structure is provided. The acoustic structure includes: an acoustic waveguide network having a main acoustic inlet and a main acoustic outlet; and at least one acoustic resonator arranged to communicate with the interior of the acoustic waveguide network via an opening in a sidewall of the acoustic waveguide network; wherein the acoustic structure is adapted to receive sound via the main acoustic inlet and, after processing the sound by the acoustic waveguide network and the at least one acoustic resonator, output processed sound via the main acoustic outlet.

[0009] It will be understood that this acoustic structure can "enhance" and "smooth" the sound emitted by loudspeakers, especially small loudspeakers, thereby significantly improving sound quality without the need for any external power or electronic circuitry.

[0010] In some embodiments, the acoustic waveguide network includes a single main acoustic waveguide and multiple branch acoustic waveguides; the entrance of the main acoustic waveguide forms the main acoustic entrance, the exit of the main acoustic waveguide branches to form multiple branch acoustic entrances of the multiple branch acoustic waveguides, and the multiple branch acoustic exits of the multiple branch acoustic waveguides collectively constitute the main acoustic exit. The aforementioned acoustic waveguide network is suitable for low-frequency boosting in the frequency range from 100Hz to the speaker's natural resonant frequency, thereby achieving a low-frequency sound pressure level (SPL) gain; in some embodiments, it can also provide SPL gain in the frequency range above the speaker's natural resonant frequency, thereby achieving an overall volume increase. In particular, the design of a single main acoustic waveguide branching into multiple branch acoustic waveguides helps ensure that sound waves do not excite specific transverse standing wave modes at that location within the operating frequency band.

[0011] In some embodiments, the plurality of branched acoustic waveguides may include two, three, four, five, six, seven, eight, or nine branched acoustic waveguides. It should be understood that the number of branched acoustic waveguides may be designed to avoid the actual need to excite specific transverse standing wave modes by acoustic waves.

[0012] In some embodiments, the at least one acoustic resonator includes a main waveguide acoustic resonator arranged to communicate with the main acoustic waveguide via an opening in the sidewall of the main acoustic waveguide. It should be understood that the function of an acoustic resonator is to generate resonance at a specific frequency, absorbing or reflecting sound waves, thus suppressing unwanted peaks in the SPL spectrum and smoothing the frequency response. Placing the resonator's opening in the path of the main acoustic waveguide ensures that all sound waves passing through the waveguide are processed.

[0013] In some embodiments, the at least one acoustic resonator includes a branch waveguide acoustic resonator arranged to communicate with the branch waveguide via an opening in the sidewall of the branch waveguide. In this way, the branch waveguide acoustic resonator can be used to further optimize the sound propagating through the branch waveguide.

[0014] In some embodiments, the cross-sectional dimensions of both the main acoustic waveguide and the branch acoustic waveguide are designed such that they do not excite transverse standing wave modes for acoustic waves in the range of 10 kHz to 20 kHz.

[0015] In some embodiments, the expansion of the cross-sectional area and / or size of the main acoustic waveguide and the branch acoustic waveguides along the acoustic path from the main acoustic inlet to the main acoustic outlet follows an exponential, hyperbolic, or linear function. It should be understood that this disclosure does not limit the expansion of the cross-sectional area and / or size of the main acoustic waveguide and the branch acoustic waveguides; other expansion patterns are also possible, as long as it can be ensured that the sound waves propagating therein do not excite transverse standing wave modes.

[0016] In some embodiments, the cross-sectional area and / or dimensions of the main acoustic waveguide and the branch acoustic waveguides are designed to gradually increase along the acoustic path from the main acoustic inlet to the main acoustic outlet. In some embodiments, the area ratio of the main acoustic outlet to the main acoustic inlet is in the range of 1 to 20. It will be understood that a larger spread ratio results in a more significant SPL improvement across the entire frequency band.

[0017] In some embodiments, the minimum cross-sectional dimension of each waveguide in the acoustic waveguide network is not less than 0.5 mm, and the maximum cross-sectional dimension is not greater than 18 mm. In some embodiments, the minimum cross-sectional dimension of each waveguide in the acoustic waveguide network is not less than 0.5 mm, and the maximum cross-sectional dimension is not greater than 9 mm. With the above design dimensions, it can be ensured that the sound waves propagating in the waveguide will not excite transverse standing wave modes within the operating frequency band, while avoiding excessive absorption of sound energy due to thermal viscous loss during sound wave propagation, thereby ensuring the sound enhancement effect.

[0018] In some embodiments, the length of the acoustic path from the main acoustic inlet to the main acoustic outlet is in the range of 10 cm to 110 cm. It will be understood that the total path length of the acoustic waveguide (the path length from the inlet to either outlet) directly affects the low-frequency extension capability. Generally, the longer the total length, the lower the lowest frequency that can be effectively enhanced.

[0019] In some embodiments, the acoustic waveguide network is designed such that the acoustic phases of the multiple branch acoustic outlets of the plurality of branch acoustic waveguides constructively interfere with each other. In this way, it can be ensured that the acoustic waves at the various acoustic outlets of the acoustic waveguide network can be effectively superimposed rather than canceled out.

[0020] In some embodiments, the acoustic waveguide network comprises only a main acoustic waveguide formed by a single acoustic channel. It will be understood that it is also possible for the acoustic waveguide network to include only the main acoustic waveguide, without branch acoustic waveguides, which can also contribute to the gain of low-frequency SPL and / or overall SPL.

[0021] In some embodiments, the cross-sectional area and / or dimensions of the main acoustic waveguide are designed to gradually converge along the acoustic path from the main acoustic inlet to the main acoustic outlet. In this way, precise enhancement and optimization of the low-frequency SPL can be achieved.

[0022] In some embodiments, the cross-sectional area and / or dimensions of the primary acoustic waveguide are designed to remain constant along the acoustic path from the primary acoustic inlet to the primary acoustic outlet. In this way, gain in low-frequency SPL and / or overall SPL can also be achieved.

[0023] In some embodiments, the acoustic resonator is a Helmholtz resonator or a quarter-wavelength resonator.

[0024] In some embodiments, the acoustic resonator is sized such that its resonant frequency is near the peak frequency that needs to be reduced.

[0025] In some embodiments, the main acoustic inlet and the main acoustic outlet face the same side or different sides of the acoustic structure.

[0026] In some embodiments, the acoustic structure unfolds in a two-dimensional plane. In some embodiments, the acoustic waveguide network and the at least one acoustic resonator reside in different two-dimensional planes. In some embodiments, the acoustic waveguide network is folded into multiple layers in three-dimensional space. In these ways, the design freedom of the acoustic structure is increased.

[0027] In some embodiments, the thickness of the acoustic structure is less than 18 mm. For example, the thickness can be less than 17 mm, 16 mm, 15 mm, 14 mm, 13 mm, 12 mm, 11 mm, 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, or 5 mm. In this case, the acoustic structure can be effectively integrated into the housing of various electronic devices themselves, or into additional housings (e.g., protective cases, brackets) of various electronic devices.

[0028] In some embodiments, the acoustic structure is integrated into the same housing. In some embodiments, the housing is adapted to serve as a casing, bracket, protective case, game console, game controller, or charging dock for an electronic device with an integrated speaker, wherein the main acoustic inlet of the acoustic structure is acoustically connected to the output side of the speaker to receive sound from the speaker.

[0029] In some embodiments, the acoustic structure includes a sound coupling component having a corresponding sound coupling inlet for coupling to the output side of the loudspeaker and guiding sound to the main acoustic inlet of the main acoustic waveguide.

[0030] In some embodiments, the acoustic structure further includes a soft sealing gasket structure adapted to couple to a sound outlet of the electronic device to couple sound from the sound outlet into the acoustic waveguide network via the main acoustic inlet. Specifically, in some embodiments, the soft sealing structure may be positioned on the sound coupling component. In some embodiments, the output side of the speaker may include the sound outlet of the electronic device.

[0031] According to a second aspect of this disclosure, an acoustic structure is provided. The acoustic structure includes: an acoustic waveguide network having a main acoustic inlet and a main acoustic outlet, and comprising a single main acoustic waveguide and multiple branch acoustic waveguides; wherein the inlet of the main acoustic waveguide forms the main acoustic inlet, the outlet of the main acoustic waveguide branches to form multiple branch acoustic inlets of the multiple branch acoustic waveguides, and the multiple branch acoustic outlets of the multiple branch acoustic waveguides collectively constitute the main acoustic outlet; wherein the acoustic structure is adapted to receive sound via the main acoustic inlet, process the sound in the acoustic waveguide network, and output the processed sound via the main acoustic outlet. It will be understood that in some application scenarios, it is possible for the acoustic structure to include only the acoustic waveguide network.

[0032] According to a third aspect of this disclosure, an acoustic assembly is provided. The acoustic assembly includes: a loudspeaker; and at least one acoustic structure as described in the first or second aspect, wherein the main acoustic inlet of the acoustic structure is acoustically connected to the output side of the loudspeaker.

[0033] According to a fourth aspect of this disclosure, an electronic device is provided, including an acoustic structure according to the first or second aspect, or an acoustic component as described in the third aspect.

[0034] According to a fifth aspect of this disclosure, an electronic device is provided, comprising: a loudspeaker integrated within a housing of the electronic device; and at least one acoustic structure according to a first or second aspect, wherein the main acoustic inlet of the acoustic structure is acoustically connected to the output side of the loudspeaker.

[0035] In some embodiments, the electronic device includes a mobile phone, tablet, game console, or game controller.

[0036] In some embodiments, the loudspeaker includes a first loudspeaker and a second loudspeaker, and the acoustic structure includes a first acoustic structure corresponding to the first loudspeaker and a second acoustic structure corresponding to the second loudspeaker.

[0037] In some embodiments, the first acoustic structure and the second acoustic structure may be structurally the same or different.

[0038] In some embodiments, the acoustic phases of the acoustic outlets of the first acoustic structure and the second acoustic structure are constructive interferences with each other. Attached Figure Description

[0039] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0040] Figure 1 shows a cross-sectional schematic diagram of a typical acoustic structure designed according to the concept of this disclosure.

[0041] Figure 2 shows the simulation results of acoustic structures without shunt design and acoustic structures with shunt design at an acoustic frequency of 6300 Hz, where (a) shows the simulation results of the waveguide without shunt design (i.e., with excessive lateral dimensions); and (b) shows the simulation results of the multipath shunt (branching) design adopted in this disclosure.

[0042] Figure 3 shows a simulation diagram illustrating the effect of different resonator opening positions on sound suppression. (a) shows the sound pressure (absolute value) distribution at 1240 Hz within a waveguide section without a resonator; (b) shows a quarter-wavelength resonator designed for approximately 1240 Hz, with its opening positioned at a distance L from the sound inlet of the waveguide; and (c) compares the exit sound pressure level (SPL) spectrum curves for different L values ​​(L = 0.003 m, 0.033 m, 0.066 m, 0.1 m).

[0043] Figure 4 shows a simulated schematic diagram of the sound pressure (absolute value) distribution of a typical branched acoustic waveguide structure.

[0044] Figure 5 shows an exemplary structural diagram of a shared resonator for two branch acoustic waveguides in a bi-branch waveguide structure, wherein (a) shows two adjacent branch acoustic waveguides connected to a resonator (quarter-wavelength resonator) through a shared connecting pipe; and (b) shows a resonator with two openings that can be placed between the two branch acoustic waveguides so that it acts on both branches simultaneously.

[0045] Figure 6 shows a structural schematic diagram of a split protective case for a dual-speaker smartphone according to a first embodiment of the present disclosure, wherein (a) shows the structure of the inner side of the assembled protective case; (b) shows the acoustic structure exposed after the back panel of the assembled protective case is removed; (c) shows a cross-sectional schematic diagram of the top portion of the acoustic structure corresponding to the top earpiece; and (d) shows a cross-sectional schematic diagram of the bottom portion of the acoustic structure corresponding to the bottom speaker.

[0046] Figure 7 shows a partial structural schematic diagram of a soft sealing gasket structure at the acoustic inlet of a protective case with integrated acoustic structure for smartphones.

[0047] Figure 8 shows the acoustic performance test for the bottom acoustic structure of Figure 6, where (a) is a schematic diagram of the test method, in which the distance between the microphone and the acoustic outlet (or sound outlet) of the acoustic structure is 10 cm during measurement; (b) is a comparison curve of SPL with and without the component installed; and (c) is a comparison curve of total harmonic distortion (THD).

[0048] Figure 9 shows the acoustic performance test for the top acoustic structure of Figure 6, where (a) is a schematic diagram of the test method, in which the distance between the microphone and the acoustic outlet (or sound outlet) of the acoustic structure is 10 cm during measurement; (b) is the SPL comparison curve with and without the component installed; and (c) is the THD comparison curve.

[0049] Figure 10 shows a schematic diagram of the structure of an integrated protective case for a smartphone design with dual speakers at the top and bottom according to a second embodiment of the present disclosure, wherein (a) is a cross-sectional schematic diagram of the acoustic structure exposed after the back panel of the protective case is removed; (b) is a perspective view of the acoustic structure; and (c) is an inner perspective view of the protective case.

[0050] Figure 11 shows the acoustic performance test of the integral protective shell of Figure 10, where (a) is a schematic diagram of the test method, in which the distance between the microphone 30 and the center of the sample is 30 cm during measurement; (b) is the SPL comparison curve with and without the protective shell; and (c) is the THD comparison curve.

[0051] Figure 12 shows a structural schematic diagram of a housing with an acoustic structure designed for only one speaker of a smartphone according to a third embodiment of the present disclosure, wherein (a) shows a cross-sectional schematic diagram of the acoustic structure exposed after the back panel of the housing is removed; (b) shows a perspective view of the housing integrating the acoustic structure; and (c) shows a perspective view of the acoustic structure from another angle.

[0052] Figures 13, 14, and 15 show the acoustic performance test results for the acoustic structure in Figure 12 with cavity thicknesses of 0.5 mm, 0.7 mm, and 0.9 mm, respectively. (a) is a schematic diagram of the test method, in which the distance between the microphone and the center of the sound outlet of the test sample is 10 cm during measurement; (b) is a comparison curve of SPL with and without the acoustic structure installed; and (c) is a comparison curve of THD.

[0053] Figure 16 shows a structural schematic diagram of a protective case designed for a tablet computer with left and right stereo dual speakers according to a fourth embodiment of the present disclosure, wherein (a) is a perspective view of the inner side of the protective case; (b) is a perspective view of the acoustic structure exposed after the back panel of the protective case is removed; and (c) is a cross-sectional schematic diagram of the acoustic structure.

[0054] Figure 17 shows the test results of the acoustic structure in Figure 16, where (a) is a schematic diagram of the test method, in which the distance between the microphone and the center of the sample is 30 cm during measurement; (b) is the SPL comparison curve with and without the protective shell; and (c) is the THD comparison curve.

[0055] Figure 18 illustrates an acoustic structure specifically designed for a woofer according to a fifth embodiment of this disclosure.

[0056] Figure 19 shows the expected numerical simulation acoustic effect of the acoustic structure in Figure 18, which shows the SPL comparison curves when the acoustic structure is installed (solid line) and when it is not installed (dashed line).

[0057] Figure 20 shows a schematic diagram of a folded, uniform cross-section acoustic structure designed for a certain game controller according to a sixth embodiment of the present disclosure, wherein (a) is a perspective view of a game controller that can be operated in conjunction with a mobile phone; (b) is a structural view of the game controller with part of its outer shell removed; (c) is a perspective view of the first layer of the acoustic structure integrated in the game controller; and (d) is a perspective view of the second layer of the acoustic structure.

[0058] Figure 21 shows a structural schematic diagram of a mobile phone charging dock design according to a seventh embodiment of the present disclosure, wherein (a) is a perspective view of the mobile phone charging dock; and (b) is a rear view of the acoustic structure integrated in the mobile phone charging dock without the back panel. Detailed Implementation

[0059] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0060] Currently, portable electronic devices (such as smartphones, tablets, and game consoles) generally suffer from poor sound quality. These problems mainly stem from the physical limitations imposed by the small size of their built-in speakers, specifically manifested as follows:

[0061] • Insufficient low-frequency response: Due to the impedance mismatch between the speaker diaphragm and the air, the bass part is weak and the sound is thin.

[0062] • Uneven high-frequency response: Due to factors such as system resonance, the sound pressure level (SPL) spectrum curve in the high-frequency part often shows unwanted sharp peaks and valleys, resulting in harsh or distorted sound.

[0063] • Insufficient SPL output across the entire frequency range: Due to the limited physical size of miniature loudspeakers and the extremely small effective displacement of the diaphragm, their overall SPL output is low, making it difficult to provide sufficient loudness.

[0064] To address these issues, traditional solutions include using conventional electronic equalizers (EQs) or introducing passive acoustic structures. However, the inventors discovered that traditional electronic equalization solutions consume power and may introduce system instability; while traditional passive acoustic solutions are limited in function and cannot simultaneously solve the aforementioned core problems.

[0065] Specifically, traditional passive acoustic solutions can be broadly categorized into the following three types:

[0066] Option 1: Use a simple acoustic horn structure for amplification / redirection. This type of technology uses a simple channel (i.e., an acoustic horn) with gradually increasing cross-sectional area set in accessories such as phone cases to guide obstructed or poorly oriented sounds to the user and provide a certain volume amplification effect.

[0067] • Option 2: Frequency response adjustment using specific geometric paths. This type of technology mainly involves designing acoustic channels with specific lengths or shapes within a limited acoustic space. By utilizing the principle of extending the sound wave propagation path, the frequency distribution characteristics of the sound are adjusted to enhance the response performance in specific frequency bands (such as the low-frequency band).

[0068] Option 3: Use independent acoustic resonators for frequency response smoothing. This type of technology integrates structures such as Helmholtz resonators into the acoustic path of electronic devices to suppress specific frequency peaks, thereby smoothing the frequency response curve of the speaker.

[0069] The design philosophy of Schemes 1 and 2 is "addition," focusing solely on how to more effectively transmit and enhance sound waves. While they can improve overall volume and low frequencies to some extent, their structure itself easily introduces or worsens new frequency peaks and troughs in the high-frequency range, resulting in an uneven spectrum. They lack a precise "peak clipping" mechanism and cannot purify the sound spectrum.

[0070] The design philosophy of the above-mentioned Scheme 3 is "subtraction," and its limitation lies in focusing only on how to suppress unwanted frequency peaks. Although they can smooth the response curve, they are completely powerless to address the fundamental problems inherent in small speakers, such as insufficient low-frequency response and insufficient overall volume.

[0071] Furthermore, all three of the above-mentioned schemes generally lack the ability to precisely control the gain and equalization of sound pressure levels across the entire frequency band, as well as the consistency of the phase of sound waves from multiple outputs, making it difficult to fundamentally improve the balance and dynamic range of the sound.

[0072] The purpose of this disclosure is to provide a novel, integrated, passive acoustic solution aimed at achieving sound pressure level gain and smooth equalization across the entire frequency range, as well as precise and consistent phase control for multi-emission sound waves, thereby solving or alleviating the problems of single function and insufficient systematic equalization capability in the aforementioned conventional technologies. To this end, the concept of this disclosure is to provide a passive physical acoustic structure that can be integrated into electronic device accessories or the device itself, designed based on the design principles of acoustic metamaterials, and used as an acoustic equalizer. Specifically, in some embodiments, the acoustic structure of this disclosure can combine acoustic elements with two different physical mechanisms and, through synergistic control of the sound wave phase, generate a hybrid, synergistic acoustic network:

[0073] • Acoustic waveguide network: A complex acoustic channel system with one inlet and at least one outlet, used to efficiently guide, transmit and enhance sound waves from loudspeakers, with a particular focus on improving low-frequency response and overall volume; through precise path design and phase coordination, the network ensures that the sound wave phase at multiple outlets within the operating frequency band meets the preset constructive interference requirements, thereby achieving excellent full-frequency sound pressure level gain.

[0074] • Acoustic resonator: One or more precisely tuned, one-end closed side resonators are strategically placed at specific locations in an acoustic waveguide network (such as the sidewall of the main waveguide, especially at the acoustic pressure antinode) to reduce the energy of the sound wave of a specific frequency propagating forward by suppressing the sound wave of that frequency (e.g., absorption or reflection) to smooth the frequency response curve.

[0075] Through the synergistic operation of these two components, this disclosure enables comprehensive "enhancement" and "smoothing" of the sound emitted by a small loudspeaker, thereby significantly improving sound quality without the need for any external power source or electronic circuitry. In some other embodiments, the improvement in sound quality can be achieved solely based on a specially designed acoustic waveguide network.

[0076] To better understand the concept of this disclosure, Figure 1 shows a cross-sectional schematic diagram of a typical acoustic structure designed according to the concept of this disclosure.

[0077] As shown in Figure 1, the acoustic structure 10 can be integrated into a housing. As an example, the housing can be, for instance, the casing of an electronic device itself with an integrated speaker, or a bracket, protective case, game console, game controller, or charging dock housing for the electronic device. Typically, the acoustic structure 10 can be formed by upper and lower plates and multiple acoustic waveguides (or acoustic channels) formed by multiple sidewalls 20 disposed between the two plates, wherein the upper and lower plates and the multiple walls 20 can constitute part of the aforementioned housing.

[0078] In use, the acoustic inlet 10-1 of the acoustic structure 10 will be acoustically connected to the output side of a speaker (not shown) of an electronic device, and after the sound is equalized or processed by the acoustic structure 10, it will be output to the outside of the acoustic structure via the acoustic outlet 10-2. Therefore, it should be understood that the acoustic structure of this disclosure will be used as a passive acoustic metamaterial equalizer.

[0079] According to some designs of this disclosure, the acoustic structure 10 includes an acoustic waveguide network 11 and at least one acoustic resonator 12. However, as will be described later, according to other designs of this disclosure, it is also possible for the acoustic structure 10 to include only a specially designed acoustic waveguide network 11.

[0080] The acoustic waveguide network 11 is the main structure for sound enhancement and spectrum shaping. As shown in Figure 1, the acoustic waveguide network 11 may have a main acoustic inlet 11-1 and a main acoustic outlet 11-2, which serve as the acoustic inlet 10-1 and acoustic outlet 10-2 of the overall acoustic structure 10.

[0081] As a non-limiting example, the acoustic waveguide network 11 in FIG1 may include only one main acoustic inlet 11-1 and multiple main acoustic outlets 11-2 (e.g., 11-2a, 11-2b, 11-2c). However, it will be understood that in other embodiments, it is possible for the acoustic waveguide network 11 to include more main acoustic inlets 11-1 and more or fewer main acoustic outlets 11-2.

[0082] In some embodiments, the acoustic waveguide network 11 may have a single main acoustic waveguide 13 and multiple branch acoustic waveguides 14. For example, the multiple branch acoustic waveguides 14 may include, for instance, two, three, four, five, six, seven, eight, or nine branch acoustic waveguides. By way of example only, FIG1 shows three branch acoustic waveguides, such as 14-a, 14-b, and 14-c. Further, as shown in FIG1, the acoustic inlet 13-1 of the main acoustic waveguide 13 may form the aforementioned main acoustic inlet 11-1, while the outlet of the main acoustic waveguide may branch to form multiple branch acoustic inlets of the aforementioned multiple branch acoustic waveguides 14-a, 14-b, and 14-c, and the individual branch acoustic outlets of the multiple branch acoustic waveguides may ultimately form the aforementioned multiple main acoustic outlets 11-2a, 11-2b, and 11-2c.

[0083] At least one acoustic resonator 12 may be arranged to communicate with the interior of the acoustic waveguide network 11 via an opening in the sidewall 20. As will be further described later, the at least one acoustic resonator 12 may communicate with the main acoustic waveguide 13 and / or the branch acoustic waveguides 14 via an opening in the sidewall defining the main acoustic waveguide 13 and / or the branch acoustic waveguides 14. Those skilled in the art will understand that the function of the at least one acoustic resonator 12 is to generate resonance at a specific frequency, absorb or reflect sound waves, and thus suppress unwanted peaks in the SPL spectrum, thereby achieving a smoothing effect on the frequency response. Typically, the physical structure of an acoustic resonator is a cavity with a specific geometry, or a section of pipe closed at one end. Typically, the acoustic resonator 12 may be, for example, a Helmholtz resonator or a quarter-wavelength resonator.

[0084] Figure 1 shows five acoustic resonators 12 as an example only. However, it should be understood that in other embodiments, there may be more or fewer acoustic resonators 12.

[0085] The propagation process of sound in the acoustic structure shown in Figure 1 is briefly described below. Specifically, in use, sound is coupled from the speaker of the electronic device into the acoustic inlet 10-1 of the acoustic structure 10, and then enters a main acoustic waveguide 13. One or more acoustic resonators 12 are integrated on the sidewalls of the main acoustic waveguide 13, so the sound wave will propagate in the main acoustic waveguide and, after preliminary processing by the resonators 12, reach a bifurcation point 13-2, where the main acoustic waveguide 13 splits into multiple branch acoustic waveguides 14-a, 14-b, and 14-c. Subsequently, the sound wave continues to propagate in its respective branch acoustic waveguide and is finally emitted from its respective acoustic outlets 11-2a, 11-2b, and 11-2c.

[0086] It is worth noting that although the acoustic waveguide and resonator in the design shown in Figure 1 exhibit a curved, folded, or meandering labyrinthine shape, those skilled in the art should understand that such complex geometry is not a necessary condition for achieving acoustic functionality, but rather a preferred engineering design choice to achieve a sufficiently long acoustic path within the compact space of electronic device accessories. As demonstrated in some later embodiments, a straighter path may also achieve the technical effects of this invention, where space permits.

[0087] The overall design concept of the above acoustic structure will be introduced below.

[0088] 1. Overall design of acoustic waveguide network (including main acoustic waveguide and branch acoustic waveguides)

[0089] 1.1 Overall Design Parameters:

[0090] a) Operating frequency band: The acoustic waveguide network disclosed herein mainly targets the frequency range (i.e., 100Hz to 700Hz or 100Hz to 600Hz) between 100Hz and the speaker's natural resonant frequency (e.g., in some embodiments, the natural resonant frequency of a mobile phone speaker is around 700Hz and the natural resonant frequency of a flat panel speaker is around 600Hz) for sound equalization, thereby achieving low-frequency SPL gain; in some embodiments, it can also perform SPL gain on the frequency range above the speaker's natural resonant frequency, thereby achieving an overall volume increase.

[0091] It should be understood that in other application scenarios, in some embodiments, the acoustic waveguide network of this disclosure can also perform low-frequency boosting on other frequency ranges. These other frequency ranges may include frequency ranges with higher upper limits and / or lower lower limits, including but not limited to, for example: 100Hz to 1kHz, 100Hz to 2kHz, 100Hz to 3kHz, 100Hz to 4kHz, 100Hz to 5kHz, 100Hz to 800Hz, 100Hz to 900Hz, 200Hz to 800Hz, 200Hz to 900Hz, 300Hz to 1kHz, etc. Furthermore, similarly, in some embodiments, it can also apply SPL gain to frequency bands above the aforementioned frequency ranges of the speaker, thereby achieving an overall volume increase.

[0092] b) Overall Volume Constraint: The acoustic waveguide network for each acoustic structure is designed to be housed within a predetermined volume. For example, for typical portable electronic devices, the volume of the acoustic waveguide network for each acoustic structure can range from 10 to 300 cubic centimeters. The design goal is to achieve optimal acoustic equalization within the given volume constraints. It should be understood that the volume of the aforementioned acoustic waveguide network may vary depending on the specific application and the available space in the electronic device.

[0093] 1.2 Morphology and geometric parameters of acoustic waveguides:

[0094] a) Basic Forms: Acoustic waveguide networks can be designed in three basic forms:

[0095] • Divergent (or horn) structure, i.e., the cross-sectional area and / or size of the acoustic waveguides (main acoustic waveguide and / or branch acoustic waveguides) are designed to gradually increase;

[0096] • Converging type (or inverted horn structure), that is: the cross-sectional area and / or size of the acoustic waveguide (main acoustic waveguide and / or branch acoustic waveguide) are designed to converge gradually;

[0097] • Constant cross-section type, that is, the cross-sectional area and / or size of the acoustic waveguide (main acoustic waveguide and / or branch acoustic waveguide) are designed to remain constant.

[0098] Divergent waveguides boost volume across the entire frequency range, making them a preferred implementation. Convergent waveguides primarily enhance low frequencies while suppressing high frequencies, and are typically used in woofers. Constant cross-section waveguides only boost low frequencies, offering no boost to mid-high frequencies. According to the design disclosed herein, except for the waveguide inlet and outlet locations, the dimensions of other waveguide positions do not necessarily strictly adhere to the following spread function at all locations; deviations within 20% are permissible in some local areas, as long as the acoustic requirements for total boost and phase difference are met.

[0099] b) Spread function: The spread of the cross-sectional area of ​​the above acoustic waveguides (including the main acoustic waveguide and the branch acoustic waveguides) from the inlet to the outlet can follow various function models, such as exponential function, hyperbolic function or linear function, etc.

[0100] c) Spread Ratio: The ratio of the total exit area to the entrance area of ​​an acoustic waveguide (spread ratio) is a key parameter determining the amount of low-frequency boost. For divergent acoustic waveguides, this ratio is typically in the range of 1 to 20. The higher the spread ratio, the more significant the SPL boost across the entire frequency band.

[0101] d) Total Length: The total path length of the acoustic waveguide (the path length from the inlet to any outlet) directly affects the low-frequency extension capability. The longer the total length, the lower the lowest frequency that can be effectively enhanced. For example, for conventional portable electronic devices, this total length can be in the range of 10 to 110 cm.

[0102] It should be noted that the SPL boost, low-frequency extension, and available volume together determine the design dimensions. It is important to note that the SPL boost and low-frequency extension may not be achievable within the available volume, and collaborative design and analysis are necessary to provide reasonable acoustic enhancement parameters.

[0103] 1.3 Multi-path routing (branching) design

[0104] a) Motivation and constraints of bifurcation: The acoustic waveguide network disclosed herein adopts a bifurcation design from a single main path to multiple branches, the key purpose of which is to actively avoid the excitation of transverse standing wave modes in the waveguide by high-frequency (e.g., 10kHz to 20kHz) acoustic waves.

[0105] When the lateral dimension of the waveguide (i.e., the dimension perpendicular to the direction of sound wave propagation) is too large, the sound waves within the waveguide will excite specific lateral standing wave modes. The sound energy of these modes is confined within the waveguide cross-section and cannot be effectively radiated along the main propagation direction. Therefore, according to the design of this disclosure, shunting is required before the lateral dimension reaches a critical value to ensure that the sound energy propagates effectively forward across the entire frequency band.

[0106] As an example, Figure 2 shows the simulation results of an acoustic structure without a shunt design and an acoustic structure with a shunt design at an acoustic frequency of 6300 Hz, wherein (a) shows the simulation results of a waveguide without a shunt design (i.e., with an excessively large lateral dimension); and (b) shows the simulation results of the multipath shunt (branching) design adopted in this disclosure.

[0107] As shown in Figure 2(a), a significant transverse standing wave mode is excited by high-frequency sound waves at the sound outlet 11'-2, resulting in a chaotic sound pressure distribution and energy confined within the waveguide cross-section, thus greatly reducing the effective sound energy radiated along the main propagation direction. In contrast, as can be seen from Figure 2(b), through a multi-path splitting (branching) design, the sound pressure phase consistency at each branch outlet 11-2a, 11-2b, and 11-2c is extremely high, allowing the sound waves to radiate effectively along the main propagation direction. Therefore, the acoustic waveguides in the above acoustic waveguide network should meet the following size constraints:

[0108] • Maximum Size Limitation: When the cross-sectional area of ​​a waveguide increases to nearly half the wavelength of a high frequency (typically between 10 kHz and 20 kHz) within the target operating frequency band, the sound waves propagating at that frequency within the waveguide will excite a transverse standing wave mode (also known as a transverse resonant mode). Since the sound energy of this resonant mode is confined within the waveguide's cross-section and cannot propagate effectively along the waveguide's main axis, this leads to a significant decrease in SPL near that frequency. Therefore, when the design requires a total width exceeding this maximum limit, the waveguide must be bifurcated before this point. Typically, the cross-section of the waveguide can be defined by two mutually perpendicular dimensions x (i.e., the width direction) and y (i.e., the thickness direction) perpendicular to the sound wave propagation direction z. Specifically, the maximum dimension of the waveguide's cross-section (in the xy plane) will not exceed 9 to 18 mm. For example, in some embodiments, the maximum dimension of the waveguide's cross-section will not exceed 8.575 mm to 17.15 mm. For example, for sound waves in a certain frequency range, the maximum cross-sectional dimension can be designed to not exceed, for example, 9 mm; while for sound waves in another frequency range, the maximum cross-sectional dimension can be designed to not exceed 18 mm. Typically, to ensure that the housing integrating the acoustic structure has a thin profile, in some embodiments, the maximum dimension of the waveguide (i.e., the air portion) of the acoustic structure in the thickness direction y can be smaller than or much smaller than the maximum dimension of the acoustic structure in the width direction x, for example, less than 3 mm or 5 mm.

[0109] • Minimum size limitation: When the minimum size of the waveguide's cross-section is too small, the thermal viscous loss of sound waves propagating within it will increase dramatically, causing excessive absorption of sound energy and failing to achieve the desired enhancement effect. Typically, the minimum size of the cross-section is no less than 0.5 mm.

[0110] b) Implementation of bifurcation: For divergent acoustic waveguides, the cross-sectional area of ​​the main acoustic waveguide gradually increases according to a predetermined function, starting from the entrance. Bifurcation is arranged at appropriate locations before the lateral dimension reaches its maximum allowable value. Depending on the overall design requirements, the entire structure may bifurcate only once or multiple times. The width of each branch acoustic waveguide after bifurcation must also adhere to the aforementioned dimensional constraints, and the widths of each branch can be designed to be the same or different.

[0111] c) Phase Coordination: To ensure that the sounds from each acoustic outlet of the acoustic waveguide network can effectively superimpose rather than cancel each other out, the geometric parameters of each branch acoustic waveguide need to be coordinating and optimized to ensure that, at all frequencies in the operating band, the acoustic wave phase of all outlets meets the following requirements:

[0112] Where N is the total number of acoustic exits in the acoustic waveguide network, and φ is the phase of the corresponding acoustic exit. Generally, phase alignment is more difficult at higher frequencies; therefore, precise control of the geometry of all waveguides at all locations is required in the design. It should be noted that the 0.7N threshold mentioned above is only set for certain application scenarios; in other embodiments, this threshold can be changed according to actual needs.

[0113] 2. Design of Acoustic Resonators

[0114] Acoustic resonators are key to achieving spectrum smoothing.

[0115] 2.1 Function and Type: Its function is to generate resonance at a specific frequency, absorbing or reflecting sound waves, thereby suppressing unwanted peaks in the SPL spectrum. Its physical structure can be a cavity with a specific geometry or a section of pipe closed at one end. In some embodiments, the acoustic resonator can be selected from either a Helmholtz resonator or a quarter-wavelength resonator.

[0116] 2.2 Geometric Parameters: The key geometric dimensions of the resonator are determined by both the resonant frequency and the required resonant intensity. Generally, for Helmholtz resonators or quarter-wavelength resonators, the resonant frequency is designed to be near the peak frequency that needs to be reduced. The aperture size of the resonator connecting to the main acoustic waveguide network depends on the magnitude of the peak volume reduction required; a larger aperture results in a greater reduction. Typically, the reduced volume will not fall below the peak-to-valley range. These two requirements jointly determine the size of the resonant unit.

[0117] To effectively suppress one or more broad peaks within a given volume constraint, a target acoustic impedance with a specific bandwidth needs to be designed. As an example, embodiments of this disclosure may draw upon existing technologies (such as those disclosed in patents WO2024 / 113402A1 and WO2024 / 165089A1) to synthesize the desired target impedance spectrum by combining one or more resonant units with different resonant frequencies, thereby achieving effective smoothing of peaks. The disclosures of patents WO2024 / 113402A1 and WO2024 / 165089A1 are hereby incorporated by reference.

[0118] 2.3 Layout Principles:

[0119] a) Preferred Layout: In most cases, to ensure that all acoustic waves passing through the waveguide are processed, the resonator opening is positioned on the sidewall of the main acoustic waveguide (i.e., before the bifurcation), upstream of the waveguide network bifurcation point. Specifically, in some embodiments, the resonator opening can be positioned in the main acoustic waveguide at the location of maximum acoustic pressure corresponding to its target frequency (i.e., at the antinode) to achieve the most efficient peak suppression.

[0120] As an example, Figure 3 shows a simulation diagram of the effect of different opening positions of the resonator on the sound suppression effect, where (a) shows the sound pressure (absolute value) distribution at a frequency of 1240 Hz in a section of the waveguide without the resonator; (b) shows a quarter-wavelength resonator designed for approximately 1240 Hz, with its opening set at a distance L from the sound inlet of the waveguide; and (c) compares the exit SPL spectrum curves for different L values ​​(L = 0.003 m, 0.033 m, 0.066 m, 0.1 m).

[0121] As shown in Figure 3(a), the sound pressure reaches its maximum value at the entrance (near L = 0); as shown in (c), when the resonator is closest to the maximum sound pressure value (i.e., L = 0.003 m, closest to the entrance), its suppression effect on the peak near 1240 Hz is most significant (as shown by the curve, this peak is greatly suppressed). This strongly demonstrates that placing the resonator at the antinode of the sound pressure wave at the target frequency can achieve the most efficient peak suppression.

[0122] b) Alternative Layout: In certain designs, the resonator can also be placed after the bifurcation of the main acoustic waveguide. The principle behind this layout is the same as the preferred layout: to achieve the most efficient peak suppression, the opening of the resonator should be placed near the maximum acoustic pressure (i.e., the antinode) corresponding to the target frequency.

[0123] As an example, Figure 4 shows a simulated schematic diagram of the sound pressure (absolute value) distribution of a typical branched acoustic waveguide structure. As can be seen from Figure 4, in a branched acoustic waveguide, the maximum sound pressure level at the target frequency is likely to occur near the middle of the branch. Therefore, placing the resonator in this vicinity can achieve the best suppression effect.

[0124] Specifically, in some embodiments, a side resonator can be independently provided for each branch acoustic waveguide that needs to be processed. In other embodiments, the branch acoustic waveguides can also adopt a shared layout, that is, two or more adjacent branch acoustic waveguides share the same resonator unit to optimize space utilization. As an example, Figure 5 shows an exemplary structural diagram of two branch acoustic waveguides sharing a resonator in a bi-branched waveguide structure, where (a) shows two adjacent branch acoustic waveguides 114-1, 114-2 connected to a resonator 12-a (quarter-wavelength resonator) through a shared connecting conduit; (b) shows a resonator 12-b with two openings that can be placed between the two branch acoustic waveguides 114-1, 114-2 so that it acts on both branches simultaneously.

[0125] 4.4 Collaborative Design for Multi-Channel and / or Multi-Speaker Systems

[0126] When the acoustic structures disclosed herein are applied to multi-channel and / or multi-speaker systems (e.g., electronic devices with stereo functionality), all acoustic waveguide networks of the multi-channel and / or multi-speaker systems must be co-designed to ensure the balance and accuracy of the stereo sound field.

[0127] a) Frequency Response Consistency: When used to construct stereo sound fields or other symmetrical acoustic systems requiring sound image balance, it is essential to ensure that the final frequency response curves of the speakers in corresponding channels (e.g., left and right) remain as consistent as possible after being enhanced by their respective acoustic structures. This requires precise design of the size and shape of the acoustic waveguide networks on both sides. Depending on the speaker characteristics and internal space constraints of the electronic device, the waveguide networks on both sides can be flexibly designed with identical, mirror-symmetrical, or different and asymmetrical shapes to ensure final acoustic balance.

[0128] b) System Phase Coordination: To ensure that sound waves from multiple channels and / or multiple speakers can effectively superimpose (constructive interference) in the listening area rather than cancel each other out due to phase inconsistency (destructive interference), a holistic phase coordination design is necessary for multi-channel and / or multi-speaker systems. This requires not only that individual acoustic waveguide networks meet their own exit phase consistency, but also that sound waves from different channels / speakers, after being processed by their respective acoustic waveguide networks, achieve spatial phase alignment in the listening area to form effective constructive interference.

[0129] The following are several embodiments of the design of acoustic structures according to this disclosure.

[0130] Example 1: Split-type protective case for dual-speaker smartphones

[0131] Figure 6 shows a structural schematic diagram of a split protective case for a dual-speaker smartphone according to a first embodiment of the present disclosure, wherein (a) shows the structure of the inner side of the assembled protective case; (b) shows the acoustic structure integrated inside the assembled protective case; (c) shows a cross-sectional schematic diagram of the top portion of the acoustic structure corresponding to the top earpiece; and (d) shows a cross-sectional schematic diagram of the bottom portion of the acoustic structure corresponding to the bottom speaker.

[0132] As a non-limiting example, the smartphone could be a smartphone with a top earpiece and a bottom main speaker (e.g., Apple smartphones). Generally, a protective case can be provided separately from the smartphone for use as an outer casing to provide additional protection.

[0133] For the aforementioned top earpiece and bottom main speaker, the protective housing 60 may integrate, for example, two independent, physically isolated acoustic structures as acoustic metamaterial equalizers for precise processing of the output of the two speakers.

[0134] Specifically, as an example only, as shown in Figures 6(b) and (c), the top acoustic structure 60A is used to process the output of the top earpiece, wherein the top acoustic structure 60A can be acoustically connected to the output side of the top earpiece via the main acoustic inlet 61'-1, and the processed sound output is performed via the main acoustic outlets 61'-2a and 61'-2b; while as shown in Figures 6(b) and (d), the bottom acoustic structure 60B is used to process the output of the bottom main speaker, wherein the bottom acoustic structure 60B can be acoustically connected to the output side of the bottom speaker via the main acoustic inlet 61-1, and the processed sound output is performed via the main acoustic outlets 61-2a, 61-2b and 61-2c.

[0135] Both the top acoustic structure 60A and the bottom acoustic structure 60B employ an acoustic structure similar to or identical to that shown in Figure 1, namely, the core hybrid architecture of this disclosure: a divergent (horn structure) acoustic waveguide network 61 or 61' for enhancing sound works in conjunction with a side acoustic resonator 62 or 62' for smoothing the spectrum. It should be noted that the structure of the top acoustic structure 60A differs from that of the bottom acoustic structure 60B. For example, compared to the bottom acoustic structure 60B, the top acoustic structure 60A has only one acoustic resonator 62' on the sidewall of its main acoustic waveguide. It should be understood that in some embodiments, it is possible to incorporate more acoustic resonators 62' into the top acoustic structure 60A. Furthermore, in some embodiments, the top acoustic structure 60A may be identical to or symmetrical with the bottom acoustic structure 60B.

[0136] To ensure the efficient operation of the acoustic structure disclosed herein, it is necessary to guarantee that sound waves from the electronic device's speaker can be completely and leak-free introduced into the sound inlet of the acoustic structure. Typically, when an electronic device (such as a smartphone) is installed in an accessory (such as a protective case), the device's sound outlet (such as the top earpiece outlet or the bottom speaker opening) should be aligned with the sound inlet of the acoustic structure.

[0137] However, since the outer frame of electronic devices and the housing of acoustic structures are usually made of rigid materials, it is difficult to form a complete airtight seal when they are in direct contact. This will cause some acoustic energy to leak directly into the external environment instead of entering the interior of the acoustic structure, which will seriously weaken the acoustic improvement effect of the acoustic structure as an equalizer.

[0138] To address this issue, in some embodiments, a sealing structure can be provided around the acoustic inlet of the acoustic structure. As an example, a sealing gasket made of a soft material (such as silicone, rubber, or foam) can be arranged around or around the edge of the acoustic inlet. When the electronic device is installed, this gasket is compressed and deformed, effectively filling the tiny gap between the device frame and the accessory housing, forming a reliable acoustic seal and ensuring that sound wave energy is guided to the acoustic waveguide network for processing to the maximum extent. As an example, Figure 7 shows a partial structural schematic of a soft sealing gasket structure at the acoustic inlet of a protective case with an integrated acoustic structure for a smartphone, where, when the smartphone is fitted inside the protective case, the bottom speaker outlet of the smartphone is aligned with the soft sealing gasket structure 70, thereby acoustically connecting the sound from the speaker to the acoustic waveguide network of the acoustic structure.

[0139] The following is a brief explanation of the design parameters of the acoustic structure shown in Figure 6.

[0140] Typically, the overall structure of the aforementioned acoustic structures 60A and 60B unfolds within a two-dimensional plane, with a consistent cavity thickness throughout, for example, 3 mm. Based on this planar design, the top and bottom acoustic structures are integrated into a compact space with a total volume of approximately 60 cubic centimeters. One of its core components is a divergent (horn-structure) acoustic waveguide network whose cross-sectional area expands exponentially from the inlet to the outlet. To achieve significant low-frequency enhancement, the expansion ratio of the total outlet area to the inlet area for the top earpiece acoustic structure 60A can be set, for example, to 2, while for the bottom speaker acoustic structure 60B, the expansion ratio can be set, for example, to 3.5. Specifically, for acoustic structure 60B, its meandering acoustic path results in a total length of, for example, approximately 190 mm. In the design, to suppress unwanted lateral standing wave modes in the high-frequency range, the lateral dimensions of the waveguides can be controlled, for example, between 3 mm and 14.5 mm. In addition, a series of quarter-wavelength resonators are integrated on its main acoustic waveguide 63 for frequency response smoothing.

[0141] The above design has been verified to deliver a significant improvement in acoustic performance. Figure 8 shows the acoustic performance test results for the bottom acoustic structure 60B of Figure 6, where (a) is a schematic diagram of the test method, in which the distance between the microphone 30 and the acoustic outlet 61-2 (or sound outlet) of the acoustic structure 60B is 10 cm during measurement; (b) is a comparison curve of SPL with and without the component installed; and (c) is a comparison curve of THD. Note: To eliminate acoustic interference from the top earpiece, the top earpiece of the smartphone was blocked during the test.

[0142] As shown in the SPL comparison curve in Figure 8(b), compared with the case without acoustic structure (dashed line), the effective frequency response lower limit after installation (solid line) significantly extends from about 1500 Hz to 473 Hz, achieving a qualitative leap in low-frequency extension capability. At the same time, considerable SPL gain is achieved throughout the entire operating frequency band.

[0143] Similarly, Figure 9 shows the acoustic performance test of the top acoustic structure 60A of Figure 6, where (a) is a schematic diagram of the test method, in which the distance between the microphone 30 and the acoustic outlet 61'-2 (or sound outlet) of the acoustic structure 60A is 10 cm during measurement; (b) is the SPL comparison curve with and without the component installed; and (c) is the THD comparison curve. Note: To eliminate acoustic interference from the bottom speaker, the bottom speaker of the smartphone was blocked during the test. As can be seen from Figure 9, it also achieves a qualitative leap in low-frequency extension capability. At the same time, it achieves considerable SPL gain throughout the entire operating frequency band.

[0144] Example 2: One-piece protective case for dual-speaker smartphones

[0145] Figure 10 shows a schematic diagram of the structure of an integrated protective case for a smartphone design with top and bottom dual speakers according to a second embodiment of the present disclosure, wherein (a) is a cross-sectional schematic diagram of the acoustic structure inside the protective case; (b) is a perspective view of the acoustic structure; and (c) is a perspective view of the inner side of the protective case.

[0146] As shown in Figure 10, unlike the split structure of Embodiment 1, this embodiment integrates the two acoustic structures 100A and 100B, corresponding to the upper and lower speakers respectively, into a single complete housing structure. Although the two acoustic processing paths remain physically isolated from each other, the integrated design makes it a fully functional independent accessory. Both acoustic structures 100A and 100B adopt the core hybrid architecture of this disclosure.

[0147] Similarly, the acoustic structure unfolds entirely within a two-dimensional plane, with a consistent cavity thickness throughout, for example, 3 millimeters. Based on this planar design, the entire acoustic structure is integrated into a compact space with a total volume of approximately 75 cubic centimeters. One of its core components is a divergent (horn-structure) acoustic waveguide network, whose cross-sectional area expands exponentially from the inlet to the outlet. To achieve significant low-frequency enhancement, for example, the expansion ratio of the total outlet area to the inlet area is set to 3.5 for the top acoustic structure 100A (top earpiece), and to 5.625 for the bottom acoustic structure 100B (bottom speaker). Specifically, for acoustic structure 100B, its meandering acoustic path results in a total length of approximately 320 millimeters. In the design, to suppress unwanted lateral standing wave modes in the high-frequency range, the lateral dimension of the waveguides in each acoustic structure is controlled between 3 millimeters and 14.5 millimeters. In addition, a series of quarter-wavelength resonators are integrated on its main waveguide for frequency response smoothing.

[0148] Due to its unibody design, its overall improvement effect on the mobile phone dual speaker system can be evaluated through a single acoustic test. Figure 11 shows the acoustic performance test of the unibody protective case, where (a) is a schematic diagram of the test method, in which the distance between the microphone 30 and the center of the sample is 30 cm during measurement; (b) is the SPL comparison curve with and without the protective case; and (c) is the THD comparison curve.

[0149] As shown in the SPL comparison curve in Figure 11(b), this design brings a significant improvement in acoustic performance: compared with the case without an equalizer (dashed line), the acoustic performance after installation (solid line) is significantly enhanced in the key mid-low frequency range, especially in the frequency range of 200 Hz to 2000 Hz, where the SPL is significantly improved.

[0150] Example 3: The Influence of Independent Acoustic Structural Functional Components and Cavity Thickness

[0151] Figure 12 shows a structural schematic diagram of a housing with an acoustic structure designed for only one speaker of a smartphone according to a third embodiment of the present disclosure, wherein (a) shows a cross-sectional schematic diagram of the acoustic structure exposed after the back panel of the housing is removed; (b) shows a perspective view of the housing integrating the acoustic structure; and (c) shows a perspective view of the acoustic structure from another angle.

[0152] As shown in Figure 12, it is not an accessory for a specific product, but a general-purpose functional component. The internal acoustic network of this acoustic structure 120 also employs the core hybrid architecture of this disclosure, characterized by a divergent (horn) structure that splits from a single main acoustic waveguide 123 into three branch acoustic waveguides 124 (e.g., 124-1, 124-2, 124-3). To facilitate sound coupling from the main acoustic waveguide 123, in some embodiments, the acoustic structure 123 may further include a sound coupling component 125, which has a corresponding sound coupling inlet 125-1 for coupling to the output side of a loudspeaker and guiding sound to the inlet 123-1 of the main acoustic waveguide 123. Furthermore, the acoustic structure 120 also includes a first resonator 122-1 connected to the main acoustic waveguide 123 and a second resonator 122-2 connected to the branch acoustic waveguides 124 for frequency response smoothing.

[0153] This embodiment aims to systematically study the impact of cavity thickness on acoustic performance. The overall structure of the acoustic structure unfolds in a two-dimensional plane. For comparative studies, three versions were specifically fabricated, with cavity thicknesses set at 0.5 mm, 0.7 mm, and 0.9 mm, respectively. Based on this planar design, its total volume is determined by both the planar area and the cavity thickness. One of its core components is a divergent (horn structure) acoustic waveguide network, whose cross-sectional area expands exponentially from the inlet to the outlet. To achieve significant low-frequency enhancement, the expansion ratio of the total outlet area to the inlet area is set to 2.8, while the meandering acoustic path results in a total length of approximately 200 mm. In the design, to suppress unnecessary lateral standing wave modes in the high-frequency band, the lateral dimensions of the main acoustic waveguide and branch acoustic waveguides are controlled between 5 mm and 13 mm.

[0154] Figures 13, 14, and 15 show the acoustic performance test results for the acoustic structure with cavity thicknesses of 0.5 mm, 0.7 mm, and 0.9 mm according to Example 3, respectively. (a) is a schematic diagram of the test method, in which the distance between the microphone and the center of the sound outlet of the sample is 10 cm during measurement; (b) is a comparison curve of SPL with and without the acoustic structure installed; and (c) is a comparison curve of THD.

[0155] The above acoustic test results clearly demonstrate the dual controllability of the acoustic structure of this disclosure and the quantitative impact of cavity thickness on performance:

[0156] a. Effective suppression of high-frequency peaks: First, a comparison of Figure 13(b), Figure 14(b), and Figure 15(b) clearly shows that the speaker unit itself has a sharp peak at approximately 5600 Hz (dashed line). After processing with this acoustic structure, regardless of whether the cavity thickness is 0.5 mm, 0.7 mm, or 0.9 mm, this peak is effectively suppressed (solid line), demonstrating the stable effectiveness of the integrated resonator in smoothing the frequency response.

[0157] b. Positive impact of thickness on sound pressure level gain: Secondly, comparing the gain effects of different thicknesses reveals a positive correlation between acoustic performance and thickness. For example, a 0.5mm thick equalizer (Figure 13(b)) mainly exhibits a significant sound pressure level boost in the mid-low frequency range of 100Hz to 500Hz; while when the thickness increases to 0.9mm (Figure 15(b)), its acoustic enhancement effect is not only higher in value, but also significantly wider in frequency coverage, achieving a superior overall gain across a broad range of 100Hz to 3000Hz.

[0158] c. Verification of Effectiveness in Ultra-Thin Structures: Finally, this embodiment also demonstrates that even under the extreme condition of a cavity thickness as thin as 0.5 mm, the acoustic structure of the present invention can still provide identifiable and meaningful acoustic improvements. This conclusion fully demonstrates the enormous potential of this technology in modern consumer electronics products that pursue ultimate thinness and lightness.

[0159] Example 4: Symmetrical Protective Case for Tablet PCs

[0160] Figure 16 shows a schematic diagram of the structure of a protective case designed for a tablet computer with left and right stereo dual speakers according to a fourth embodiment of the present disclosure, wherein (a) is a perspective view of the inner side of the protective case; (b) is a perspective view of the acoustic structure exposed after the back panel of the protective case is removed; and (c) is a plan view of the acoustic structure.

[0161] As shown in Figure 16, to ensure the balance and accuracy of the stereo sound field, two geometrically almost mirror-symmetrical acoustic structures 160A and 160B are integrated inside the protective shell, corresponding to the right channel speaker and the left channel speaker, respectively. Unlike the previous embodiments, the acoustic structure of this embodiment focuses on using acoustic waveguide network technology to achieve maximum sound pressure level gain. However, it should be understood that although the structure in Figure 16 is shown to use only pure acoustic waveguide network technology, in practical applications, relevant resonators can also be introduced as needed.

[0162] The acoustic structure design parameters of one side are used as an example for illustration. The overall structure of this equalizer network unfolds in a two-dimensional plane, with a consistent cavity thickness of 3 mm throughout. Based on this planar design, the entire acoustic structure is integrated into a compact space with a total volume of approximately 230 cubic centimeters. At its core is a complex and precise divergent (horn structure) acoustic waveguide network, splitting from a single main path 163 into six branches, ultimately radiating acoustic energy outward through six outlets: two at the top (i.e., 161-2a, 161-2b) and four at the bottom (161-2c, 161-2d, 161-2e, 161-2f). The cross-sectional area of ​​this network expands exponentially from the inlet to the outlet, with the ratio of the total outlet area to the inlet area set at 18, and the meandering acoustic path resulting in a total length of approximately 620 mm. In the design, to suppress unnecessary transverse standing wave modes in the high-frequency band, the maximum transverse dimension of the waveguide is controlled between 3 mm and 15 mm.

[0163] The pure waveguide network design in this embodiment aims to maximize the sound pressure level gain across the entire frequency band. Figure 17 shows the relevant acoustic performance test results of the acoustic structure in Figure 16, where (a) is a schematic diagram of the test method, in which the distance between the microphone and the center of the sample is 30 cm during measurement; (b) is the SPL comparison curve with and without the protective shell; and (c) is the THD comparison curve.

[0164] As shown in the SPL comparison curve in Figure 17(b), this design delivers a loud and balanced improvement in acoustic performance: compared to when the equalizer is not installed (dashed line), after installation (solid line), a significant improvement in sound pressure level is achieved in an extremely wide operating frequency band from 100 Hz to 5000 Hz, bringing a more immersive and full audio-visual entertainment experience to the tablet computer.

[0165] Example 5: Equalizer using a convergent acoustic waveguide

[0166] Figure 18 illustrates an acoustic structure designed specifically for a woofer according to a fifth embodiment of this disclosure, one of the core features of which is the use of a convergent (inverted horn) acoustic waveguide network. This embodiment is designed to achieve precise enhancement and optimization of low-frequency sound pressure levels.

[0167] As shown in Figure 18, firstly, unlike the aforementioned embodiment which uses a meandering folding design for compact integration, the acoustic waveguide 181 and multiple resonators 182 in this embodiment both adopt a non-folding geometry. The acoustic inlet 181-1 of the acoustic waveguide 181 is acoustically connected to the speaker 80, while the resonators 182 are coupled to the end of the acoustic waveguide 181 near the acoustic inlet 181-1.

[0168] Secondly, the design parameters of this acoustic structure are optimized to suit the characteristics of the subwoofer. The cross-sectional area of ​​the acoustic waveguide 181 gradually shrinks from the acoustic inlet 181-1 to the acoustic outlet 181-2 according to a functional law. As one of the core designs, the shrinkage ratio of the total outlet area to the inlet area of ​​this convergent waveguide is set to 0.54, and the total length is 500 mm.

[0169] As an example, the aforementioned multiple resonators 182 are a series of quarter-wavelength resonators used for precise suppression of clutter in specific mid-to-high frequency bands.

[0170] Figure 19 shows the expected numerical simulation acoustic effect of the acoustic structure in Figure 18, which shows the SPL comparison curves when the acoustic structure is installed (solid line) and when it is not installed (dashed line).

[0171] As shown in the acoustic effect diagram in Figure 19, this convergent structure can significantly improve the low-frequency sound pressure level below 150 Hz. This low-pass filtering characteristic makes it very suitable as an acoustic matching network for woofers, effectively enhancing the power and depth of bass.

[0172] As can be seen from the above embodiments, the meandering maze-like shape is merely an engineering spatial optimization choice, rather than a necessary condition for achieving the acoustic effects of this disclosure.

[0173] Example 6: Three-dimensional folding structure integrated into a game controller

[0174] Figure 20 shows a schematic diagram of a folded, uniform cross-section acoustic structure in three-dimensional space designed for a certain game controller according to a sixth embodiment of the present disclosure, wherein (a) is a perspective view of a game controller that can be operated in conjunction with a mobile phone; (b) is a partial structural view of the game controller with part of its outer shell removed; (c) is a perspective view of the first layer of the acoustic structure integrated in the game controller; and (d) is a perspective view of the second layer of the acoustic structure.

[0175] As shown in Figures 20(a) and (b), in order to match the left and right speakers of a smartphone in landscape mode, the game controller 200 integrates two geometrically mirror-symmetrical acoustic structures 200L and 200R inside.

[0176] The design parameters of this embodiment have the following characteristics. Unlike the aforementioned designs that unfold in a two-dimensional plane, this embodiment makes full use of the relatively ample internal three-dimensional space of the game controller. Its core acoustic waveguide network adopts a constant cross-sectional shape and folds and winds around in three-dimensional space.

[0177] For example, the acoustic structure 200L on the left side has a first acoustic structure 200L1 and a second acoustic structure 200L2. Specifically, the first acoustic structure 200L1 is designed to have a transverse waveguide section 200L1-1 and a curved waveguide section 200L1-2. The acoustic inlet 200L1-1a of the transverse waveguide section 200L1-1 is in acoustic communication with the output of a loudspeaker (e.g., the left loudspeaker of a game console clipped onto a game controller). Furthermore, the acoustic outlet 200L1-1b of the transverse waveguide section 200L1-1 is acoustically connected to the acoustic inlet 200L2-1a of the second acoustic structure 200L2, and is acoustically connected to the acoustic inlet 200L1-2a of the curved waveguide section 200L1-2 of the first acoustic structure 200L1 via the acoustic outlet 200L2-1b of the second acoustic structure 200L2, and is connected to the sound outlet 200-a of the outer shell 220 of the game controller 200 via the acoustic outlet 200L1-2b of the curved waveguide section 200L1-2.

[0178] Therefore, the sound transmission path of the aforementioned acoustic structure 200L is as follows: the sound from the speaker (e.g., the left speaker of a game console clipped onto the game controller) will first enter the transverse waveguide section 200L1-1 of the first layer acoustic structure 200L1 via the acoustic inlet 200L1-1a, and then enter the second layer acoustic structure 200L2 via the acoustic outlet 200L1-1b. After transmission is completed in the second layer acoustic structure 200L2, the sound will return to the first layer acoustic structure 200L1 via the acoustic outlet 200L2-1b. Finally, after transmission is completed in the curved waveguide section 200L1-2 of the first layer acoustic structure 200L1, the sound will be output to the outside of the game controller via the acoustic outlets 200L1-2b and 200-a.

[0179] According to the design, the above-mentioned double-layer three-dimensional bypass technology can achieve an extremely long effective sound path within a limited projected area, with a total length of up to 1030 mm, for example.

[0180] This long-path, constant-section design aims to maximize the extension of the low-frequency response. According to acoustic principles, a longer path effectively amplifies lower-frequency sound waves. Therefore, this design is expected to deliver a more immersive bass effect for game audio, making sounds like explosions and engine roars more impactful and powerful.

[0181] It should be noted that although the structure shown in Figure 20 uses only acoustic waveguide network technology, in practical applications, relevant resonators can also be introduced as needed.

[0182] Example 7: Linearly growing waveguide structure integrated into charging base

[0183] Figure 21 shows a structural schematic diagram of a mobile phone charging dock design according to a seventh embodiment of the present disclosure, wherein (a) is a perspective view of the mobile phone charging dock; and (b) is a rear view of the acoustic structure integrated in the mobile phone charging dock.

[0184] As shown in Figure 21, to match the left and right speakers of a smartphone in landscape mode, the charging dock 90 integrates two acoustic structures 210L and 210R corresponding to the left and right speakers. Once the phone is placed on the charging dock 90, the sound from its speakers can be directed into the acoustic structure 210 integrated inside the charging dock.

[0185] As shown in the figure, the entire acoustic structure unfolds within a two-dimensional plane, with a consistent cavity thickness of 3 millimeters throughout. Its core is a divergent acoustic waveguide network, unique in that its cross-sectional area expands linearly from the inlet to the outlet, meaning the waveguide width (or area) increases linearly with the path length. The expansion ratio of the network's total outlet area to its inlet area is set to 2, resulting in a total length of approximately 200 millimeters and lateral dimensions controlled between 8 and 16 millimeters.

[0186] This embodiment aims to demonstrate that the present invention can flexibly employ various waveguide spreading functions. Using a linear spreading function is expected to provide a balanced and stable full-band sound pressure level gain characteristic, effectively improving the loudness and fullness of the audio when the phone is played aloud on the dock, and significantly enhancing the user's auditory experience in scenarios such as watching videos and making video calls.

[0187] Similarly, it should be noted that although the structure shown in Figure 21 uses only acoustic waveguide network technology, in practical applications, relevant resonators can also be introduced as needed.

[0188] The various embodiments of this disclosure have been described in detail above, and it will be understood that the acoustic structure of this disclosure has the following advantages:

[0189] 1) Synergistic and comprehensive equalization capabilities: This disclosure is not a simple superposition of functions, but rather a solution to contradictions that cannot be resolved by a single technical approach. For example, while acoustic waveguide networks (such as horn structures) enhance low frequencies and overall sound pressure levels, the high-frequency peaks they introduce are precisely addressed by the synergistically integrated resonators. This synergistic effect of "1+1>2" achieves both "addition" and "subtraction" processing of the sound spectrum, with functionality far exceeding that of existing technologies.

[0190] 2) Superior acoustic performance: Through the precise design of multi-path splitting and phase coordinated control, the frequency response curve is finely shaped, significantly improving low-frequency performance, increasing overall volume and smoothing high-frequency fluctuations.

[0191] 3) High design flexibility: The core principle of this invention can be applied to various acoustic waveguide forms (divergent, convergent, and uniform cross-section) and can be flexibly laid out according to different product forms (2D plane or 3D space).

[0192] 4) Passive and high stability: As a purely physical structure, it requires no additional power supply, has no electromagnetic interference, and has high system stability.

[0193] 5) Maintaining or improving fidelity: Test data from multiple embodiments show that the pure physical equalizer of this disclosure can maintain or even improve the total harmonic distortion level of the speaker system while significantly increasing the sound pressure level. This ensures that the sound quality is enhanced without a decrease in fidelity, avoiding the introduction of additional distortion.

[0194] It should be understood that the technical solution disclosed herein provides a low-cost, high-efficiency sound quality enhancement solution for the vast consumer electronics market. It can serve as an "enabling technology," directly integrating into electronic devices such as mobile phones, tablets, and game consoles to optimize their native sound quality, and also significantly enhancing the product value and user experience of traditional accessories such as phone cases, game controllers, and charging docks, thus possessing enormous market potential.

[0195] It should also be understood that this disclosure may also relate to embodiments relating to the following provisions.

[0196] 1. An acoustic structure comprising:

[0197] An acoustic waveguide network with a main acoustic inlet and a main acoustic outlet; and

[0198] At least one acoustic resonator is arranged to communicate with the interior of the acoustic waveguide network via an opening in the sidewall of the acoustic waveguide network;

[0199] The acoustic structure is adapted to receive sound via the main acoustic inlet and, after processing the sound through the acoustic waveguide network and the at least one acoustic resonator, output the processed sound via the main acoustic outlet.

[0200] 2. The acoustic structure according to Clause 1, wherein the acoustic waveguide network comprises a single main acoustic waveguide and multiple branch acoustic waveguides;

[0201] The entrance of the main acoustic waveguide forms the main acoustic entrance, the exit of the main acoustic waveguide branches to form multiple branch acoustic entrances of multiple branch acoustic waveguides, and the multiple branch acoustic exits of the multiple branch acoustic waveguides together constitute the main acoustic exit.

[0202] 3. The acoustic structure according to Clause 2, wherein the plurality of branched acoustic waveguides comprises two, three, four, five, six, seven, eight or nine branched acoustic waveguides.

[0203] 4. The acoustic structure according to any one of clauses 2 to 3 above, wherein the at least one acoustic resonator includes a main waveguide acoustic resonator, the main waveguide acoustic resonator being arranged to communicate with the main acoustic waveguide via an opening in the sidewall of the main acoustic waveguide.

[0204] 5. The acoustic structure according to any one of the preceding clauses 2 to 4, wherein the at least one acoustic resonator comprises a branch waveguide acoustic resonator, the branch waveguide acoustic resonator being arranged to communicate with the branch acoustic waveguide via an opening in the sidewall of the branch acoustic waveguide.

[0205] 6. The acoustic structure according to any one of the preceding clauses 2 to 5, wherein the cross-sectional dimensions of the main acoustic waveguide and the branch acoustic waveguide are designed such that no transverse standing wave modes are excited for sound waves in the range of 10 kHz to 20 kHz.

[0206] 7. The acoustic structure according to any one of the preceding clauses 2 to 6, wherein the expansion law of the cross-sectional area and / or size of the main acoustic waveguide and the branch acoustic waveguide along the acoustic path from the main acoustic inlet to the main acoustic outlet follows an exponential function, a hyperbolic function or a linear function.

[0207] 8. The acoustic structure according to any one of the preceding clauses 2 to 7, wherein the cross-sectional area and / or size of the main acoustic waveguide and the branch acoustic waveguide are designed to gradually increase along the acoustic path from the main acoustic inlet to the main acoustic outlet.

[0208] 9. The acoustic structure according to Clause 1, wherein the acoustic waveguide network comprises only a primary acoustic waveguide formed by a single acoustic conduit.

[0209] 10. The acoustic structure according to any one of clauses 1 to 9, wherein the ratio of the area of ​​the main acoustic outlet to the area of ​​the main acoustic inlet is in the range of 1 to 20.

[0210] 11. The acoustic structure according to any one of clauses 1 to 10, wherein the minimum dimension of the cross-section of each waveguide in the acoustic waveguide network is not less than 0.5 mm and the maximum dimension is not greater than 18 mm.

[0211] 12. The acoustic structure according to Clause 11, wherein the minimum cross-sectional dimension of each waveguide in the acoustic waveguide network is not less than 0.5 mm and the maximum cross-sectional dimension is not greater than 9 mm.

[0212] 13. The acoustic structure according to any one of Clauses 2 to 3, wherein the acoustic waveguide network is designed such that the acoustic phases of the multiple branch acoustic outlets of the plurality of branch acoustic waveguides constructively interfere with each other.

[0213] 14. The acoustic structure according to any one of clauses 1-6 and 9, wherein the cross-sectional area and / or dimensions of the main acoustic waveguide are designed to gradually converge along the acoustic path from the main acoustic inlet to the main acoustic outlet.

[0214] 15. An acoustic structure according to any one of clauses 1-6 and 9, wherein the cross-sectional area and / or dimensions of the main acoustic waveguide are designed to remain constant along the acoustic path from the main acoustic inlet to the main acoustic outlet.

[0215] 16. The acoustic structure according to any one of the preceding clauses, wherein the acoustic resonator is a Helmholtz resonator or a quarter-wavelength resonator.

[0216] 17. The acoustic structure according to any one of the preceding clauses, wherein the dimensions of the acoustic resonator are designed such that its resonant frequency is near the peak frequency to be reduced.

[0217] 18. The acoustic structure according to any one of the preceding clauses, wherein the main acoustic inlet and the main acoustic outlet face the same side or different sides of the acoustic structure.

[0218] 19. The acoustic structure according to any one of the preceding clauses, wherein the acoustic structure unfolds in a two-dimensional plane.

[0219] 20. The acoustic structure according to any one of the preceding clauses, wherein the acoustic waveguide network and the at least one acoustic resonator are in different two-dimensional planes.

[0220] 21. The acoustic structure according to any one of the preceding clauses 1 to 18, wherein the acoustic waveguide network is folded into multiple layers in three-dimensional space.

[0221] 22. The acoustic structure according to any one of the preceding clauses, wherein the thickness of the acoustic structure is less than 18 mm.

[0222] 23. The acoustic structure according to any one of the preceding clauses, wherein the length of the acoustic path from the main acoustic inlet to the main acoustic outlet is in the range of 10 cm to 110 cm.

[0223] 24. The acoustic structure according to any one of the preceding clauses, wherein the acoustic structure is integrated on the same housing.

[0224] 25. The acoustic structure according to Clause 24, wherein the housing is adapted to serve as a casing, bracket, protective case, game console, game controller, or charging dock for an electronic device with an integrated speaker, wherein the main acoustic inlet of the acoustic structure is adapted to be acoustically connected to the output side of the speaker to receive sound from the speaker.

[0225] 26. The acoustic structure according to Clause 25, wherein the acoustic structure includes a sound coupling component having a corresponding sound coupling inlet for coupling to the output side of the loudspeaker and directing sound to the main acoustic inlet of the main acoustic waveguide.

[0226] 27. The acoustic structure according to any one of the preceding clauses further includes a soft sealing gasket structure adapted to be coupled to a sound outlet of an electronic device so as to couple sound from the sound outlet into the acoustic waveguide network via the main acoustic inlet.

[0227] 28. An acoustic structure comprising:

[0228] An acoustic waveguide network having a main acoustic inlet and a main acoustic outlet, and comprising a single main acoustic waveguide and multiple branch acoustic waveguides;

[0229] The main acoustic waveguide has an inlet forming the main acoustic inlet, and the main acoustic waveguide has an outlet branching to form multiple branch acoustic waveguides with multiple branch acoustic inlets. The multiple branch acoustic waveguides with multiple branch acoustic outlets together constitute the main acoustic outlet.

[0230] The acoustic structure is adapted to receive sound via the main acoustic inlet, process the sound in the acoustic waveguide network, and output the processed sound via the main acoustic outlet.

[0231] 29. The acoustic structure according to Clause 28, wherein the plurality of branched acoustic waveguides comprises two, three, four, five, six, seven, eight or nine branched acoustic waveguides.

[0232] 30. The acoustic structure according to any one of the preceding clauses 28 to 29, wherein the cross-sectional dimensions of the main acoustic waveguide and the branch acoustic waveguide are designed such that no transverse standing wave modes are excited for acoustic waves in the range of 10 kHz to 20 kHz.

[0233] 31. The acoustic structure according to any one of the preceding clauses 28 to 30, wherein the expansion law of the cross-sectional area and / or size of the main acoustic waveguide and the branch acoustic waveguides along the acoustic path from the main acoustic inlet to the main acoustic outlet follows an exponential function, a hyperbolic function or a linear function.

[0234] 32. The acoustic structure according to any one of the preceding clauses 28 to 31, wherein the cross-sectional area and / or size of the main acoustic waveguide and the branch acoustic waveguide are designed to gradually increase along the acoustic path from the main acoustic inlet to the main acoustic outlet.

[0235] 33. The acoustic structure according to any one of the preceding clauses 28 to 32, wherein the ratio of the area of ​​the main acoustic outlet to the area of ​​the main acoustic inlet is in the range of 1 to 20.

[0236] 34. The acoustic structure according to any one of the preceding clauses 28 to 33, wherein the minimum dimension of the cross-section of each waveguide in the acoustic waveguide network is not less than 0.5 mm and the maximum dimension is not greater than 18 mm.

[0237] 35. The acoustic structure according to Clause 34, wherein the minimum cross-sectional dimension of each waveguide in the acoustic waveguide network is not less than 0.5 mm and the maximum cross-sectional dimension is not greater than 9 mm.

[0238] 36. An acoustic structure according to any one of clauses 28 to 35, wherein the acoustic waveguide network is designed such that the acoustic phases of the multiple branch acoustic outlets of the plurality of branch acoustic waveguides constructively interfere with each other.

[0239] 37. The acoustic structure according to any one of clauses 28 to 30, 33 to 36, wherein the cross-sectional area and / or dimensions of the main acoustic waveguide are designed to gradually converge along the acoustic path from the main acoustic inlet to the main acoustic outlet.

[0240] 38. The acoustic structure according to any one of clauses 28 to 30, 33 to 36, wherein the cross-sectional area and / or dimensions of the main acoustic waveguide are designed to remain constant along the acoustic path from the main acoustic inlet to the main acoustic outlet.

[0241] 39. The acoustic structure according to any one of the preceding clauses 28 to 38, wherein the main acoustic inlet and the main acoustic outlet face the same side or different sides of the acoustic structure.

[0242] 40. The acoustic structure according to any one of the preceding clauses 28 to 39, wherein the acoustic structure unfolds in a two-dimensional plane.

[0243] 41. The acoustic structure according to any one of the preceding clauses 28 to 39, wherein the acoustic waveguide network is folded into multiple layers in three-dimensional space.

[0244] 42. The acoustic structure according to any one of the preceding clauses 28 to 41, wherein the thickness of the acoustic structure is less than 18 mm.

[0245] 43. The acoustic structure according to any one of the preceding clauses 28 to 42, wherein the length of the acoustic path from the main acoustic inlet to the main acoustic outlet is in the range of 10 cm to 110 cm.

[0246] 44. The acoustic structure according to any one of the preceding clauses 28 to 43, wherein the acoustic structure is integrated on the same housing.

[0247] 45. The acoustic structure according to Clause 44, wherein the housing is adapted to serve as a casing, bracket, protective case, game console, game controller, or charging dock for an electronic device with an integrated speaker, wherein the main acoustic inlet of the acoustic structure is adapted to be acoustically connected to the output side of the speaker to receive sound from the speaker.

[0248] 46. ​​The acoustic structure according to Clause 45, wherein the acoustic structure includes a sound coupling component having a corresponding sound coupling inlet for coupling to the output side of the loudspeaker and directing sound to the main acoustic inlet of the main acoustic waveguide.

[0249] 47. The acoustic structure according to any one of the preceding clauses 28 to 46 further includes a soft sealing gasket structure adapted to be coupled to a sound outlet of an electronic device so as to couple sound from the sound outlet into the acoustic waveguide network via the main acoustic inlet.

[0250] 48. An acoustic component comprising:

[0251] loudspeakers; and

[0252] At least one acoustic structure according to any one of the clauses, wherein the main acoustic inlet of the acoustic structure is acoustically connected to the output side of the loudspeaker.

[0253] 49. An electronic device comprising the acoustic components described in Clause 48.

[0254] 50. An electronic device comprising:

[0255] A speaker integrated within the housing of the electronic device; and

[0256] At least one acoustic structure according to any one of clauses 1 to 47, wherein the main acoustic inlet of the acoustic structure is acoustically connected to the output side of the loudspeaker.

[0257] 51. The electronic device as described in Clause 50, wherein the electronic device includes a mobile phone, tablet, game console, and game controller.

[0258] 52. The electronic device according to any one of clauses 50 to 51, wherein the loudspeaker includes a first loudspeaker and a second loudspeaker, and the acoustic structure includes: a first acoustic structure corresponding to the first loudspeaker and a second acoustic structure corresponding to the second loudspeaker.

[0259] 53. The electronic device according to Clause 52, wherein the first acoustic structure and the second acoustic structure are structurally identical or different.

[0260] 54. The electronic device according to clause 52 or 53, wherein the acoustic phases of the acoustic outlets of the first acoustic structure and the second acoustic structure are constructively interfering with each other.

[0261] While the invention has been detailed and described in the accompanying drawings and foregoing description, these descriptions and descriptions should be considered illustrative or exemplary rather than restrictive; the invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments will be understood and practiced by those skilled in the art in practicing the claimed invention through study of the drawings, disclosure, and appended claims.

[0262] In the claims, the word "comprising" does not exclude other elements, and the indefinite articles "a" or "an" do not exclude a plurality. A single element or other unit may fulfill the function of multiple items set forth in the claims. The mere fact that certain features are recited only in dissimilar embodiments or dependent claims does not imply that combinations of these features cannot be used advantageously. Without departing from the spirit and scope of this application, the scope of protection of this application covers any possible combination of the various features recited in the various embodiments or dependent claims.

Claims

1. An acoustic structure comprising: an acoustic waveguide network having a primary acoustic inlet and a primary acoustic outlet; and at least one acoustic resonator arranged to communicate with the interior of the acoustic waveguide network via an opening on a sidewall of the acoustic waveguide network; wherein the acoustic structure is adapted to receive sound via the primary acoustic inlet and output processed sound via the primary acoustic outlet after the sound is processed by the acoustic waveguide network and the at least one acoustic resonator.

2. The acoustic structure of claim 1, wherein the acoustic waveguide network comprises a single primary acoustic waveguide and a plurality of branched acoustic waveguides; an inlet of the primary acoustic waveguide forms the primary acoustic inlet, an outlet of the primary acoustic waveguide bifurcates to form a plurality of branched acoustic inlets of the plurality of branched acoustic waveguides, and a plurality of branched acoustic outlets of the plurality of branched acoustic waveguides collectively constitute the primary acoustic outlet.

3. The acoustic structure of claim 2, wherein the plurality of branched acoustic waveguides comprises two, three, four, five, six, seven, eight, or nine branched acoustic waveguides.

4. The acoustic structure of any one of the preceding claims 2 to 3, wherein the at least one acoustic resonator comprises a primary waveguide acoustic resonator arranged to communicate with the primary acoustic waveguide via an opening on a sidewall of the primary acoustic waveguide.

5. The acoustic structure of any one of the preceding claims 2 to 4, wherein the at least one acoustic resonator comprises a branched waveguide acoustic resonator arranged to communicate with the branched acoustic waveguide via an opening on a sidewall of the branched acoustic waveguide.

6. The acoustic structure of any one of the preceding claims 2 to 5, wherein the primary acoustic waveguide and the branched acoustic waveguides are each designed with cross-sectional dimensions such that no transverse standing wave modes are excited for acoustic waves in the range of 10 kHz to 20 kHz.

7. The acoustic structure of any one of the preceding claims 2 to 6, wherein the expansion of the cross-sectional area and / or dimensions of the primary acoustic waveguide and the branched acoustic waveguides follows an exponential function, a hyperbolic function, or a linear function along an acoustic path from the primary acoustic inlet to the primary acoustic outlet.

8. The acoustic structure of any one of the preceding claims 2 to 7, wherein the cross-sectional area and / or dimensions of the primary acoustic waveguide and the branched acoustic waveguide are designed to gradually increase along an acoustic path from the primary acoustic inlet to the primary acoustic outlet.

9. The acoustic structure of claim 1, wherein the acoustic waveguide network comprises only a primary acoustic waveguide formed by a single acoustic duct.

10. The acoustic structure of any one of claims 1 to 9, wherein the ratio of the area of the primary acoustic outlet to the primary acoustic inlet is in the range of 1 to 20.

11. The acoustic structure of any one of claims 1 to 10, wherein the minimum dimension of the cross-section of each waveguide in the acoustic waveguide network is not less than 0.5 mm and the maximum dimension is not greater than 18 mm. ​ 12. The acoustic structure according to claim 11, wherein the minimum cross-sectional dimension of each waveguide in the acoustic waveguide network is not less than 0.5 mm and the maximum cross-sectional dimension is not greater than 9 mm.

13. The acoustic structure according to any one of claims 2 to 3, wherein the acoustic waveguide network is designed such that the acoustic phases of the multiple branch acoustic outlets of the plurality of branch acoustic waveguides constructively interfere with each other.

14. The acoustic structure according to any one of claims 1-6 and 9, wherein the cross-sectional area and / or dimensions of the main acoustic waveguide are designed to gradually converge along the acoustic path from the main acoustic inlet to the main acoustic outlet.

15. The acoustic structure according to any one of claims 1-6 and 9, wherein the cross-sectional area and / or dimensions of the main acoustic waveguide are designed to remain constant along the acoustic path from the main acoustic inlet to the main acoustic outlet.

16. The acoustic structure according to any one of the preceding claims, wherein the acoustic resonator is a Helmholtz resonator or a quarter-wavelength resonator.

17. The acoustic structure according to any one of the preceding claims, wherein the dimensions of the acoustic resonator are designed such that its resonant frequency is near the peak frequency to be reduced.

18. The acoustic structure according to any one of the preceding claims, wherein the main acoustic inlet and the main acoustic outlet face the same side or different sides of the acoustic structure.

19. The acoustic structure according to any one of the preceding claims, wherein the acoustic structure unfolds in a two-dimensional plane.

20. The acoustic structure according to any one of the preceding claims, wherein the acoustic waveguide network and the at least one acoustic resonator are in different two-dimensional planes.

21. The acoustic structure according to any one of claims 1 to 18, wherein the acoustic waveguide network is folded into multiple layers in three-dimensional space.

22. The acoustic structure according to any one of the preceding claims, wherein the thickness of the acoustic structure is less than 18 mm.

23. The acoustic structure according to any one of the preceding claims, wherein the length of the acoustic path from the main acoustic inlet to the main acoustic outlet is in the range of 10 cm to 110 cm.

24. The acoustic structure according to any one of the preceding claims, wherein the acoustic structure is integrated on the same housing.

25. The acoustic structure of claim 24, wherein the housing is adapted to serve as a casing, bracket, protective case, game console, game controller, or charging dock for an electronic device with an integrated speaker, wherein the main acoustic inlet of the acoustic structure is acoustically connected to the output side of the speaker to receive sound from the speaker.

26. The acoustic structure according to claim 25, wherein the acoustic structure includes a sound coupling component having a corresponding sound coupling inlet for coupling to the output side of the loudspeaker and guiding sound to the main acoustic inlet of the main acoustic waveguide.

27. The acoustic structure according to any one of the preceding claims further includes a soft sealing gasket structure adapted to be coupled to a sound outlet of an electronic device so as to couple sound from the sound outlet into the acoustic waveguide network via the main acoustic inlet.

28. An acoustic structure comprising: An acoustic waveguide network having a main acoustic inlet and a main acoustic outlet, and comprising a single main acoustic waveguide and multiple branch acoustic waveguides; The main acoustic waveguide has an inlet forming the main acoustic inlet, and the main acoustic waveguide has an outlet branching to form multiple branch acoustic waveguides with multiple branch acoustic inlets. The multiple branch acoustic waveguides with multiple branch acoustic outlets together constitute the main acoustic outlet. The acoustic structure is adapted to receive sound via the main acoustic inlet, process the sound in the acoustic waveguide network, and output the processed sound via the main acoustic outlet.

29. An acoustic component comprising: speaker; as well as At least one acoustic structure according to any one of claims 1 to 28, wherein the main acoustic inlet of the acoustic structure is acoustically connected to the output side of the loudspeaker.

30. An electronic device comprising the acoustic component of claim 29.

31. An electronic device, comprising: A speaker integrated into the housing of the electronic device; as well as At least one acoustic structure according to any one of claims 1 to 28, wherein the main acoustic inlet of the acoustic structure is acoustically connected to the output side of the loudspeaker.

32. The electronic device of claim 31, wherein the electronic device is selected from a mobile phone, a tablet, a game console, or a game controller.

33. The electronic device of any of claims 31-32, wherein the speaker comprises a first speaker and a second speaker, and the acoustic structure comprises: A first acoustic structure corresponding to the first loudspeaker, and a second acoustic structure corresponding to the second loudspeaker.

34. The electronic device of claim 33, wherein the first acoustic structure and the second acoustic structure are structurally identical or different.

35. The electronic device according to claim 33 or 34, wherein the acoustic wave phases of the acoustic outlets of the first acoustic structure and the second acoustic structure are constructive interferences with each other.

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