Ultrasonic attenuation for transducers

Abstract

The invention relates to ultrasonic attenuation for a transducer. A transducer attenuator assembly includes a housing defining an acoustic cavity coupled to a sound output port of a transducer operable to generate an audible frequency from an ultrasonic frequency; and a plurality of openings formed through the housing to acoustically couple the acoustic cavity to an ambient environment, and arranged to attenuate ultrasonic waves and leak audible acoustic waves output by the transducer to the acoustic cavity.

Description

[0001] Cross Reference to Related Applications This application is a non-provisional of co-pending U.S. Provisional Patent Application No. 63 / 674,684, filed July 23, 2024, and U.S. Provisional Patent Application No. 63 / 811,325, filed May 23, 2025, which are incorporated by reference herein. TECHNICAL FIELD

[0002] One aspect of the present disclosure relates to an attenuator for attenuating ultrasonic frequencies while leaking low frequencies associated with a transducer. Other aspects are also described and claimed. BACKGROUND

[0003] Portable communication or listening devices (e.g., smart phones, earphones, etc.) have one or more transducers located within them that convert input electrical audio signals to sound pressure wave outputs that can be heard by a user or convert sound pressure wave inputs to electrical audio signals. The transducers (e.g., speakers) can be used, for example, to output sound pressure waves corresponding to a far-end user’s voice (such as during a phone call), or to output sound pressure waves corresponding to sounds associated with a game the user wants to play or music the user wants to play. Because the profile of the portable device is relatively thin, the profile of the transducers is also relatively thin, which can make it difficult to maintain optimal sound quality. Additionally, for health and safety reasons, it can be desirable to attenuate certain ultrasonic amplitudes or frequency ranges output by the transducers or otherwise output near a user’s ear, while still outputting lower frequencies to the user’s ear. SUMMARY

[0004] Aspects of the present disclosure relate to attenuators for attenuating ultrasonic frequencies associated with a transducer or speaker architecture (e.g., a microelectromechanical system (MEMS) transducer) that uses ultrasonic frequencies to generate audio frequencies. Representatively, when audio tones are produced using a MEMS transducer that operates at high frequencies, some ultrasonic energy can inevitably be present at the eardrum in addition to the lower frequencies or sounds that are desired at the eardrum. For example, a MEMS transducer or speaker can use ultrasonic modulation and demodulation techniques to generate audible sound. Ultrasonic modulation and demodulation speaker techniques use amplitude modulated ultrasonic waves along the amplitude of an intended audio signal to generate audible sound from the modulated ultrasonic. The modulated ultrasonic is demodulated to produce the intended audible sound output. However, it is difficult to separate the ultrasonic energy from the lower frequency audible sound that is desired near the ear. Accordingly, aspects of the present disclosure relate to attenuator architectures for use with transducers that use ultrasonic frequencies to generate audio frequencies to attenuate undesirable ultrasonic frequencies or energy near the ear. In some aspects, the attenuator attenuates the undesirable ultrasonic frequencies to be in the range of less than 94 decibels (dB), or more preferably in the range of 7 dB to 40 dB.

[0005] In some aspects, this disclosure relates to a transducer attenuator assembly comprising: a housing defining an acoustic cavity coupled to a sound output port of a transducer, the transducer being operable to generate audible frequencies from ultrasonic frequencies; and a plurality of openings formed through the housing to acoustically connect the acoustic cavity to the surrounding environment, the plurality of openings being arranged to attenuate ultrasonic waves and leak audible sound waves output by the transducer into the acoustic cavity. In some aspects, at least one of the plurality of openings is aligned with a point of minimum pressure of the ultrasonic waves. In other aspects, the housing comprises a rectangular tube having an end coupled to the sound output port of the transducer, a side arranged perpendicular to the end, and a plurality of openings formed through the side. In still other aspects, ultrasonic waves form a longitudinal standing wave within the acoustic cavity, and each of the plurality of openings is aligned with a point of minimum pressure of the longitudinal standing wave. In some aspects, the housing comprises a disk having a first side and a second side, the first side including a central opening acoustically coupled to the sound output port of the transducer, the second side being arranged parallel to the first side, and a plurality of openings formed through the second side. In another aspect, ultrasonic waves form a meridional standing wave within the acoustic cavity, and each of the plurality of openings is aligned with the point of minimum pressure of the meridional standing wave. In some aspects, the plurality of openings are arranged in a concentric ring pattern along a second side of the disk. In another aspect, the housing includes a cone having a first side and a second side, the first side including a apex with a central opening coupled to the acoustic output port of the transducer, the second side being arranged parallel to the first side, through which the plurality of openings are formed. In other aspects, at least one of the plurality of openings defines a main channel extending from the acoustic cavity to the surrounding environment, and an auxiliary channel extending from the sidewall of the main channel, the auxiliary channel being tuned to attenuate ultrasonic waves. In some aspects, the assembly further includes: a housing coupled to a side of the housing through which the plurality of openings are formed, and the housing having a port to the surrounding environment; and a chip-level attenuator acoustically coupled to the port to attenuate residual ultrasonic frequency waves within the housing. In some aspects, at least one of the plurality of openings comprises an opening cluster. A protective film and a movable tuning plate can be further arranged above the opening cluster, and the movable tuning plate can be operated to open the opening within the opening cluster aligned with the point of minimum pressure of the ultrasonic wave and close the opening within the opening cluster that is misaligned with the point of minimum pressure.

[0006] In other aspects, a portable electronic device includes a device housing having a housing wall defining an internal cavity isolated from the surrounding environment; a transducer attenuator coupled to the device housing and defining an acoustic cavity within the internal cavity, the acoustic cavity being coupled to a sound output port of the transducer, and the transducer being operable to generate audible sound waves from ultrasound; and a plurality of openings formed through the transducer attenuator to acoustically connect the acoustic cavity to the surrounding environment, and at least one of the plurality of openings being aligned with a point of minimum pressure of the ultrasound waves output by the transducer to the acoustic cavity. In some aspects, the plurality of openings are aligned with a plurality of points of minimum pressure of the ultrasound waves to attenuate the ultrasound waves and leak audible sound waves output by the transducer into the acoustic cavity. In other aspects, the transducer attenuator includes a sealed-end transmission line having a length that is an integer multiple of the length of the ultrasound waves output by the transducer, and the plurality of openings are arranged along the length of the transmission line such that at least one opening is aligned with a point of minimum pressure of the ultrasound waves. In some aspects, the transducer attenuator includes a hollow disk having a first side and a second side, the first side including a central opening coupled to the sound output port of the transducer, and the second side arranged parallel to the first side, with a plurality of openings formed through the second side. In other aspects, ultrasonic waves form a meridional standing wave within the acoustic cavity, and each of the plurality of openings is aligned with the point of minimum pressure of the meridional standing wave. In some aspects, the transducer attenuator includes a cone having a first side and a second side, the first side including a apex having a central opening coupled to the sound output port of the transducer, and the second side arranged parallel to the first side, with a plurality of openings formed through the second side. In other aspects, at least one of the plurality of openings defines a main channel extending from the acoustic cavity to the surrounding environment, and an auxiliary channel extending from a sidewall of the main channel, the auxiliary channel being tuned to attenuate ultrasonic waves. In some aspects, a housing is coupled to a side of the transducer attenuator through which the plurality of openings are formed, the housing having a port to the surrounding environment, and a chip-level attenuator acoustically coupled to the port to attenuate residual ultrasonic waves within the housing. In other aspects, the device housing includes a wearable device housing.

[0007] The above overview does not include an exhaustive list of all aspects of this disclosure. It is contemplated that this disclosure encompasses all systems and methods that can be implemented by all suitable combinations of the aspects outlined above and the various aspects disclosed in the detailed embodiments below and specifically pointed out in the claims filed with this patent application. Such combinations have specific advantages not specifically described in the above overview. Attached Figure Description

[0008] Several aspects are illustrated in the accompanying drawings by way of example rather than limitation, and similar reference numerals in the drawings indicate similar elements. It should be noted that references to “a” or “an” in this disclosure do not necessarily refer to the same aspect, and that they mean at least one.

[0009] Figure 1 A cross-sectional side view of one aspect of the attenuator assembly is shown.

[0010] Figure 2 Examples Figure 1 A perspective view of the attenuator component.

[0011] Figure 3 This illustrates another aspect of the attenuator assembly: a cross-sectional side view.

[0012] Figure 4 Examples Figure 3 A top view of one aspect of the attenuator component.

[0013] Figure 5 This illustrates another aspect of the attenuator assembly: a cross-sectional side view.

[0014] Figure 6A This illustrates another aspect of the attenuator assembly: a cross-sectional side view.

[0015] Figure 6B Examples Figure 6A An enlarged cross-sectional perspective view of one aspect of the attenuator assembly.

[0016] Figure 7 Examples Figure 6A Another aspect of the attenuator assembly is shown in an enlarged cross-sectional perspective view.

[0017] Figure 8 This illustrates another aspect of the attenuator assembly: a cross-sectional side view.

[0018] Figure 9 This illustrates another aspect of the attenuator assembly: a cross-sectional side view.

[0019] Figure 10 Examples Figure 9 A top view of the attenuator component.

[0020] Figure 11 Examples Figure 9 A top view of another aspect of the attenuator component.

[0021] Figure 12 This is a top view illustrating another aspect of the attenuator assembly.

[0022] Figure 13 Examples of what can be achieved therein are provided. Figures 1-12 A block diagram of one aspect of an electronic device containing an attenuator component. Detailed Implementation

[0023] In this section, we will explain several preferred aspects of this disclosure with reference to the accompanying drawings. Where the shape, relative position, and other aspects of the described components are not clearly defined, the scope of this disclosure is not limited to the components shown, which are for illustrative purposes only. Furthermore, while many details are set forth, it should be understood that some aspects of this disclosure can be implemented without these details. In other instances, well-known structures and techniques have not been shown in detail so as not to obscure the understanding of this description.

[0024] The terminology used herein is for the purpose of describing particular aspects only and is not intended to limit this disclosure. Spatially related terms, such as “below,” “under,” “down,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship of one element or feature to one or more other elements or features, as illustrated in the accompanying drawings. It should be understood that spatially related terms are intended to cover different orientations of the device in use or operation other than those shown in the accompanying drawings. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features may be oriented “above” other elements or features. Thus, the exemplary term “below” can cover both the orientations of above and below. The device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially related descriptors used herein are interpreted accordingly.

[0025] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context otherwise indicates. It should be further understood that the terms “comprising” and / or “including” define the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0026] The terms “or” and “and / or” as used herein should be interpreted as including or referring to any one or any combination thereof. Therefore, “A, B, or C” or “A, B, and / or C” means “any one of the following: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition will only occur if the combination of elements, functions, steps, or actions is inherently mutually exclusive in some way.

[0027] Figure 1A cross-sectional side view of one aspect of an attenuator assembly is illustrated. The attenuator assembly 100 may include a housing or enclosure 102 having one or more walls or portions sealed together to form an internal cavity or chamber 106 isolated from the surrounding environment 104. The housing or enclosure 102 may be a relatively rigid structure forming an electronic device housing. Typically, in some aspects, the housing or enclosure 102 may form an earpiece or wearable device housing, such as a temple or arm of glasses resting on the ear. In some aspects, the portion or wall may be considered a fixed structure that may be snap-fitted, welded, adhered, or attached together in a sealing manner to form a housing 102 of a desired type. The internal chamber 106 defined by the housing 102 may contain a transducer 124 configured to generate audible sound that can be output to the surrounding environment 104, and more specifically, to the ear of a nearby user. In some aspects, the transducer 124 may be a microelectromechanical system (MEMS) transducer or loudspeaker that uses ultrasonic modulation and demodulation techniques to generate audible sound. Ultrasonic modulation and demodulation loudspeaker technology uses amplitude-modulated ultrasound waves that follow the amplitude of a desired audio signal to generate audible sound from modulated ultrasound. The modulated ultrasound is then demodulated to produce the desired audible sound output. However, in addition to the audible sound, there may also be ultrasonic frequencies that are output to the surrounding environment.

[0028] To reduce the output of ultrasonic frequencies to the surrounding environment, and more specifically, to the area near the ear, transducer 124 may be coupled to attenuator 108, which is configured to attenuate undesirable ultrasonic frequencies output by transducer 124 before reaching the surrounding environment 104. Typically, attenuator 108 may be connected at one end to the sound output port 125 of transducer 124 and is configured to allow audible or desired sound output or otherwise leak to the surrounding environment 104 while attenuating or otherwise preventing undesirable ultrasonic or frequency output. Typically, attenuator 108 may be formed by one or more walls 110, 112, 114, 116 connected to housing 102 and defining acoustic cavity 107. For example, attenuator 108 may include sidewalls 110 and 116, which extend parallel to each other and are connected by endwalls 114 that close or otherwise seal the ends of acoustic cavity 107. The other end wall 112 of attenuator 108 may be open or otherwise formed into an opening and connected to transducer 124. Transducer 124 may output sound waves 120, 122 into acoustic cavity 107 of attenuator 108. Attenuator 108 may also include a plurality of openings 118A, 118B, 118C located between acoustic cavity 107 and surrounding environment 104 to output audible sound or audible sound waves into surrounding environment 104 (e.g., into the ears of a nearby user). Openings 118A-C may be formed at locations and / or sites along side wall 110 of attenuator 108, selected to output or otherwise leak audible sound waves or desired sound waves into surrounding environment 104 through openings 118A-C, while attenuating or otherwise preventing undesirable ultrasonic frequencies from leaking through openings 118A-C.

[0029] Typically, as previously discussed, transducer 124 can output audible sound using modulation / demodulation techniques by generating a carrier frequency and / or modulator frequency, which can be output into the acoustic cavity 107 of attenuator 108, as represented by sound wave 120. The carrier frequency and / or modulator frequency represented by sound wave 120 can be in the ultrasonic frequency range that is not desired to be output to the surrounding environment (e.g., near the user's ear) through openings 118A-C. To attenuate these undesirable ultrasonic frequencies, attenuator 108 may have a length that is an integer (N) multiple of the wavelength of the carrier frequency and / or modulator frequency represented by sound wave 120. Sound wave 120 (e.g., representing the carrier frequency) forms a longitudinal wave within acoustic cavity 107, which has a pressure minimum point represented by a valley or zero point 120A and a pressure maximum point represented by a peak point 120B along its length. This pattern can be called a standing wave because the advancing wave and the reflected wave coincide at the same location along the same time interval. In the case of another sound wave 122 with a frequency much lower than the ultrasonic frequency within the acoustic cavity 107 (e.g., a demodulated audible tone of about 1 kHz desired to be output to the user's ear), the pressure minimum or zero point 122A and the pressure maximum or peak point 122B of wave 122 will not share all the same locations of the standing wave 120. Instead, as shown, sound wave 122 may have a pressure maximum or peak point 122B at a location along attenuator 108, which coincides with some pressure minimum or zero points 120A of sound wave 120. At the pressure minimum point, there will be no or only minimal energy flow (e.g., close to zero pressure), while at the pressure maximum point, there will be maximum energy flow. Therefore, as shown, forming openings 118A-C along the attenuator sidewall 110 at locations coinciding with the minimum pressure point 120A of the high-frequency wave 122 (e.g., an ultrasonic frequency wave) and the maximum pressure point of the low-frequency wave 120 (e.g., an audible frequency wave) will allow the desired audible tone represented by the low-frequency wave 122 to leak from openings 118A-C, without leaking through openings 118A-C or only leaking to a minimal extent the ultrasonic frequency represented by wave 120. In this respect, attenuator 108 outputs the desired audio tone (e.g., within the audible frequency range) from transducer 124 to the surrounding environment 104 while attenuating undesirable ultrasonic frequencies (e.g., within the ultrasonic frequency range).

[0030] Various aspects of the attenuator 108 can be tuned to achieve the desired attenuation of the ultrasonic frequency, which will be discussed below. Figure 2 Please provide a detailed explanation. Figure 2 Examples Figure 1A side perspective view of attenuator 108 is shown. As can be seen from this view, attenuator 108 may have an elongated rectangular shape defined by its length dimension (L), height dimension (H), and width dimension (W). Additionally, each of the openings 118A-C formed through the sidewall 110 may be acoustically connected to channels 218A, 218B, 218C extending from the sidewall 110 into the surrounding environment 104. The size and / or dimensions of any one or more of these aspects of attenuator 108 can be selected to attenuate desired ultrasonic frequencies. Typically, the selectivity of attenuator 108 in attenuating some frequencies while simultaneously attenuating others can be defined by the size or number of openings 118A-C and / or channels 118A-C. For example, the narrower the openings 118A-C and / or channels 218A-C, the greater the selectivity and ability to prevent ultrasonic frequencies from leaking from attenuator 108. However, the openings 118A-C and / or channels 218A-C should not be so narrow that the output and overall efficiency at the desired leakage frequency decrease. Therefore, the openings 118A-C and / or channels 218A-C can be tuned to have a size, shape, and / or dimension that prevents ultrasonic frequency leakage while still maximizing the desired audible tone output. For example, in some aspects, the openings 118A-C and channels 218A-C may have a relatively narrow polygonal shape as shown. Additionally, the greater the number of openings 118A-C and associated channels 218A-C, the larger the desired audio band output. However, since the openings 118A-C must coincide with the minimum pressure point or null of the carrier frequency 120, and there is a finite number of carrier frequency nulls within the acoustic cavity 107, the sidewalls of the attenuator 108 can be increased to meet higher output requirements. For example, the length (L), height (H), or width (W) of the sidewalls 110, 112, 114, 116, and / or 210 can be increased to meet higher output requirements. Additionally, as previously discussed, the length (L) can be an integer (N) multiple (e.g., N x wavelength) of the wavelength of the frequency (e.g., carrier frequency) represented by the sound wave 120. In this respect, if a higher carrier frequency is chosen, the attenuator size (e.g., length (L)) can be reduced to achieve the desired attenuation. Alternatively, if the desired number of openings 118A-C is greater than the number allowed by the attenuator size (e.g., to improve audio band output), a higher carrier frequency with a greater number of zero-point values ​​can be chosen, which in turn allows for a greater number of openings 118A-C along the attenuator 108. In the illustrated configuration, three openings 118A-C are exemplified; however, it is contemplated that more or fewer openings can be formed through the sidewall 110 of the attenuator 108. Furthermore, although the openings 118A-C and the associated channels 218A-C are shown along the sidewall 110, it is contemplated that they can be formed along different sidewalls, such as sidewall 116, depending on the desired direction of the sound output.Additionally, although transducer 124 is shown attached to end wall 112 and outputs sound waves in a direction parallel to the side walls 110, 116 and perpendicular to the direction of sound output through openings 118A-C, it is contemplated that transducer 124 may be attached to other portions or walls of attenuator 108 (e.g., end wall 114). Furthermore, it should be understood that in some respects, openings 118A-C may not be open all the way to the closed end 114 of attenuator 108. Instead, to support the accumulation of standing waves within attenuator 108, one or both openings of openings 118A-C, such as openings 118B and 118C, may be closed. This helps the standing waves achieve a higher pressure gradient between peaks and zeros, thereby allowing air nonlinear demodulation to become more efficient in demodulation.

[0031] Now for reference Figure 3 , Figure 3 A cross-sectional side view of another aspect of attenuator assembly 300 is illustrated. Attenuator assembly 300 includes similar aspects and operates in a similar manner to attenuator assembly 100 to attenuate ultrasonic frequencies while leaking audible tones. However, attenuator assembly 300 has a different geometry than attenuator assembly 100. Typically, attenuator assembly 300 may include attenuator 308 having a hollow disk or cylindrical geometry and being coupled at its center to transducer 324 to radiate sound waves from the center of attenuator 308. For example, similar to Figures 1-2The attenuator assembly 300 may include a housing or enclosure 102 having one or more walls or portions sealed together to form an internal cavity or chamber 106 that houses the transducer 324 and is isolated from the surrounding environment 104. The transducer 324 may be a microelectromechanical system (MEMS) transducer or loudspeaker that uses ultrasonic modulation and demodulation techniques to form audible sound. However, in addition to audible sound, the transducer may also output ultrasonic frequencies. To attenuate undesirable ultrasonic frequencies, the transducer 324 may be coupled to an attenuator 308, which is configured to attenuate undesirable ultrasonic frequencies output by the transducer 324 before reaching the surrounding environment 104 (e.g., the ear of a nearby user). Typically, the attenuator 308 may be connected at its center to the transducer 324 and is configured to allow audible or desired sound output or otherwise leak into the surrounding environment 104 while attenuating or otherwise preventing the output of undesirable ultrasonic frequencies. For example, attenuator 308 may be formed by one or more walls 310, 316 connected to housing 102 and defining a hollow acoustic cavity 307. Wall 310 may have a circular shape, and wall 316 may have a similar shape and extend parallel to wall 310. Both walls 310 and 316 may be planar or flat walls, which are sealed to each other around their edges by side walls 326, 328 to form a generally cylindrical acoustic cavity 307. Wall 316 of attenuator 308 may have an opening 314 at its center to which transducer 324 is coupled. Transducer 324 may output sound waves 320, 322 into acoustic cavity 307 of attenuator 308. In some aspects, sound waves 320, 322 may form meridional standing waves within acoustic cavity 307. The attenuator 308 may also include a plurality of openings 318A, 318B, 318C, 318D, 318E, 318F located between the acoustic cavity 307 and the surrounding environment 104 to output audible sound or audible sound waves to the surrounding environment 104 (e.g., to the ears of a nearby user). The openings 318A-F may be formed at locations and / or sites along the wall 310 of the attenuator 308, which are selected to output or otherwise leak audible sound waves or desired sound waves to the surrounding environment 104 through the openings 318A-F, while attenuating or otherwise preventing undesirable ultrasonic frequencies from leaking through the openings 318A-F.

[0032] Typically, as previously discussed, transducer 324 can output audible sound using modulation / demodulation techniques by generating a carrier frequency and / or modulator frequency, which can be output as a radial standing wave represented by sound waves 320, 322 into the acoustic cavity 307 of attenuator 308. The carrier frequency and / or modulator frequency represented by sound waves 320, 322 can be in the ultrasonic frequency range where it is not desirable to output to the surrounding environment (e.g., near the user's ear) through openings 318A-F. To attenuate these undesirable ultrasonic frequencies, openings 318A-F of attenuator 308 can be formed at locations along attenuator wall 310 coinciding with the point of minimum pressure 320A of sound waves 320, 322. On the one hand, these ultrasonic frequencies will not leak through openings 318A-F. On the other hand, much lower audible tones will have points of maximum pressure coinciding with openings 318A-F, allowing lower audible tones to leak from openings 318A-F to the surrounding environment 104. In this respect, attenuator 308 outputs the desired audio tone (e.g., lower frequencies in the audible frequency range) from transducer 324 to the surrounding environment 104, while attenuating undesirable ultrasonic frequencies (e.g., within the ultrasonic frequency range).

[0033] In some respects, although Figure 3 Only six openings 318A-F are visible in the cross-sectional view, but more than six openings 318A-F may exist, together forming an opening pattern along the wall 310, such as... Figure 4 The illustrated top view is shown. Representatively, Figure 3 This can be understood as an example along Figure 4 A side view of the cross-section of line 3-3. (As shown from...) Figure 4 As can be seen in the top view of the illustrated attenuator 308, openings 318A-F form a pattern of concentric rings 402, 404, and 406 across the wall 310. For example, the openings can be arranged to form an inner ring 406, a middle ring 404, and an outer ring 402 radiating outwards from the axis of symmetry 330 of the attenuator 308. In this respect, the maximum number of openings can be aligned with each of the zero points of the audible frequencies and the points of maximum pressure within the acoustic cavity 307 to maximize the output of the desired audio tone while attenuating undesirable ultrasonic frequencies.

[0034] Figure 5A cross-sectional side view illustrating another aspect of the attenuator assembly is shown. Attenuator assembly 500 includes similar aspects and operates in a manner similar to attenuator assemblies 100 and 300 to attenuate ultrasonic frequencies while leaking audible tones. However, attenuator assembly 500 has a geometry different from the geometries of the attenuators previously discussed. Typically, attenuator assembly 500 may include attenuator 508 having a hollow conical, funnel-shaped, or V-shaped geometry and being coupled at its center or apex to transducer 524 to radiate sound waves from the center of attenuator 508. For example, similar to... Figures 1-4The attenuator assembly 500 may include a housing or enclosure 102 having one or more walls or portions sealed together to form an internal cavity or chamber 106 that houses the transducer 524 and is isolated from the surrounding environment 104. In some aspects, the transducer 524 may be a microelectromechanical system (MEMS) transducer or loudspeaker that uses ultrasonic modulation and demodulation techniques to form audible sound. However, in addition to audible sound, the transducer may also output ultrasonic frequencies as previously discussed. To attenuate undesirable ultrasonic frequencies, the transducer 524 may be coupled to an attenuator 508, which is configured to attenuate undesirable ultrasonic frequencies output by the transducer 524 before reaching the surrounding environment 104. Typically, the attenuator 508 may be connected to the acoustic output port of the transducer 524 through an opening 514 at its apex and is configured to allow audible or desired sound output or otherwise leak into the surrounding environment 104 while attenuating or otherwise preventing the output of undesirable ultrasonic frequencies. For example, attenuator 508 may be formed by one or more walls 510, 516 connected to housing 102 and defining a hollow acoustic cavity 507. In some aspects, wall 510 may be considered a top wall or sound output wall and has a conical, funnel-shaped, V-shaped, or other non-planar shape, and wall 516 may be considered a bottom wall having a complementary shape similar to wall 510, such that it extends parallel to wall 510. Both walls 510 and 516 may be sealed to each other around their edges by side walls 526, 528 to form a generally cylindrical acoustic cavity 507. Wall 516 of attenuator 508 (e.g., bottom wall) may have an opening 514 at its center or apex to which transducer 524 is coupled. Transducer 524 may output sound waves 520 into the acoustic cavity 507 of attenuator 508. The attenuator 508 may also include a plurality of openings 518A, 518B, 518C, 518D, 518E, 518F located between the acoustic cavity 507 and the surrounding environment 104 to output audible sound or audible sound waves to the surrounding environment 104 (e.g., to the ears of a nearby user). The openings 518A-F may be formed at locations and / or sites along the wall 510 of the attenuator 508 (e.g., the top wall or sound output wall), chosen to output or otherwise leak audible sound waves or desired sound waves to the surrounding environment 104 through the openings 518A-F, while attenuating or otherwise preventing undesirable ultrasonic frequencies from leaking through the openings 518A-F. Typically, the carrier frequency and / or modulator frequency represented by the sound wave 520 may be within the ultrasonic frequency range where output to the surrounding environment (e.g., near the user's ears) through the openings 518A-F is not desired. To attenuate these unwanted ultrasonic frequencies, the openings 518A-F of the attenuator 508 can be formed at locations along the attenuator wall 510 that coincide with the point of minimum pressure 520A of the sound wave 520. This prevents these ultrasonic frequencies from leaking through the openings 518A-F.On the other hand, much lower audible tones will have the point of maximum pressure coinciding with openings 518A-F, allowing lower audible tones to leak from openings 518A-F into the surrounding environment 104. Additionally, although... Figure 5 Only six openings 518A-F are visible in the cross-sectional view, but more than six openings 518A-F may exist, together forming a shape similar to the wall 510. Figure 4 The illustrated top view shows the opening pattern. Typically, openings 518A-F form a pattern of concentric rings 502, 504, and 506 across wall 510. For example, openings 518A-F can be arranged to form an inner ring 502, a middle ring 504, and an outer ring 506 that radiate outward from the axis of symmetry 530 of attenuator 508 to achieve maximum ultrasonic frequency attenuation and desired audible sound output.

[0035] Figure 6A A cross-sectional side view of another aspect of the attenuator assembly is illustrated. Attenuator assembly 600 includes a similar aspect and operates in a manner similar to attenuator assemblies 100, 300, and 500 to attenuate ultrasonic frequencies while leaking audible tones. However, attenuator assembly 600 has an opening geometry different from the opening geometries previously discussed. Typically, attenuator assembly 600 may include attenuator 608 having any of the geometries previously discussed (e.g., a hollow disk geometry) and being centrally coupled to transducer 624 to radiate sound waves from the center of attenuator 608. For example, similar to... Figures 1-5The attenuator assembly 600 may include a housing or enclosure 102 having one or more walls or portions sealed together to form an internal cavity or chamber 106 that houses the transducer 624 and is isolated from the surrounding environment 104. In some aspects, the transducer 624 may be a microelectromechanical system (MEMS) transducer or loudspeaker that uses ultrasonic modulation and demodulation techniques to form audible sound (e.g., to be output to a user's ear). However, in addition to audible sound, the transducer may also output ultrasonic frequencies as previously discussed. To attenuate undesirable ultrasonic frequencies, the transducer 624 may be coupled to an attenuator 608, which is configured to attenuate undesirable ultrasonic frequencies output by the transducer 624 before reaching the surrounding environment 104. Typically, the attenuator 608 may be connected to the sound output port of the transducer 624 through an opening 614 at its center and is configured to allow audible or desired sound output or otherwise leak into the surrounding environment 104 while attenuating or otherwise preventing the output of undesirable ultrasonic frequencies. For example, attenuator 608 may be formed by one or more walls 610, 616 connected to housing 102 and defining a hollow acoustic cavity 607. Both walls 610, 616 may be sealed to each other around their edges by side walls 626, 628 to form a generally cylindrical acoustic cavity 607. A wall 616 of attenuator 608 (e.g., a bottom wall) may have an opening 614 at its center to which a transducer 624 is coupled. Transducer 624 may output sound waves 620 into the acoustic cavity 607 of attenuator 608. Attenuator 608 may also include a plurality of openings 618A, 618B, 618C, 618D, 618E located between acoustic cavity 607 and the surrounding environment 104 to output audible sound or audible sound waves to the surrounding environment 104 (e.g., to the ears of a nearby user). Openings 618A-E may be formed at locations and / or points along the wall 610 of attenuator 608 (e.g., a sound output wall), chosen to allow audible or desired sound waves to be output or otherwise leaked into the surrounding environment 104 through openings 618A-E, while attenuating or otherwise preventing undesirable ultrasonic frequencies from leaking through openings 618A-E. Typically, the carrier frequency and / or modulator frequency represented by sound wave 620 may be within the ultrasonic frequency range that is not desired to be output into the surrounding environment (e.g., near the user's ear) through openings 618A-E. To attenuate these undesirable ultrasonic frequencies, openings 618A-E of attenuator 608 may be formed at locations along the attenuator wall 610 coinciding with the point of minimum pressure 620A of sound wave 620. In this way, these ultrasonic frequencies will not leak through openings 618A-E. On the other hand, much lower audible tones will have the point of maximum pressure coinciding with openings 618A-E, allowing lower audible tones to leak from openings 618A-E into the surrounding environment 104.Although only five openings 518A-E can be seen in the cross-sectional view of Figure 6, there may be more than five openings 618A-E, which together form a similar shape along the wall 610. Figure 4 The illustrated top view pattern, such as an open ring.

[0036] Additionally, in some aspects, one or more of the openings 618A-E may also have a geometry configured to interact with ultrasound and produce destructive interference to further attenuate any residual ultrasound frequencies passing through the openings 618A-E. Representatively, as from... Figure 6B As can be seen from the enlarged perspective view of the illustrated opening 618D, opening 618D includes a channel 613 that generates parallel paths for ultrasonic sound waves and attenuates any residual ultrasonic tones through destructive interference generated by their interaction. Typically, opening 618D may include a main channel 613 having a first end 615 to the acoustic cavity 607 and a second end 617 to the surrounding environment 104. The main channel 613 may extend generally parallel to the direction of the sound output by transducer 624, or in other words, parallel to the axis of symmetry 630. One or more optional auxiliary channels 626, 628 may branch off from the main channel 613 or be otherwise acoustically coupled to the main channel. For example, auxiliary channels 626, 628 may be C-shaped channels or tubes or lateral U-shaped channels or tubes extending from the sidewalls of the main channel 613. Typically, one end of channels 626, 628 may be connected to and open near a first end 615 of the main channel 613, and the other end of channels 626, 628 may be connected to and open near a second end 617 of the main channel 613. In some respects, channels 626, 628 may be horizontally aligned with each other as shown, or may be vertically offset. In other respects, it is contemplated that the main channel 613 and / or auxiliary channels 626, 628 may have different lengths and / or geometries to attenuate different ultrasonic frequencies. Typically, one or more auxiliary channels may have, for example, […]. Figure 7 The illustrated spiral configuration. For example, the auxiliary channel can be formed by a channel 726 having a first end 726A, which extends to and connects to the end 617 of the main channel 613 near that end. Figure 7 As shown, channel 726 spirals from the first end 726A around the main channel 613 to the second end 726B, and the second end connects to the end 615 of the main channel 613 and is located near that end.

[0037] Furthermore, it should be understood that although a main channel 613 with auxiliary channels 626, 628 is shown, the auxiliary channels 626, 628 can be omitted, and the main channel 613 can individually have a geometry including a specific length and / or a specific width to attenuate residual ultrasonic frequencies. In this respect, the geometry of the main channel 613 and / or the auxiliary channels 626, 628, individually or in combination, can generate parallel paths of ultrasonic waves and attenuate residual ultrasonic peaks through destructive interference generated by their interaction, similar to the concept of a miniature Herschel-Quake (HQ) tube. It should also be understood that although... Figure 6B It describes Figure 6A The opening is 618D, but refer to... Figure 6B The described opening geometry can be applied to Figure 6A Any of the openings 618A-E shown, or previously referenced Figures 1-5 The opening being discussed.

[0038] Figure 8 A cross-sectional side view illustrating another aspect of the attenuator assembly is shown. Attenuator assembly 800 may include similar aspects and operate in a manner similar to attenuator assemblies 100, 300, 500, and 600 to attenuate ultrasonic frequencies while simultaneously leaking audible tones. However, attenuator assembly 800 may also include an ultrasonic attenuator chip coupled to an attenuator output port or opening to introduce a second stage of attenuation. Typically, attenuator assembly 800 may include attenuator 808 having any of the geometries previously discussed (e.g., a hollow disk geometry) and coupled at its center to transducer 824 to radiate sound waves from the center of attenuator 808. For example, similar to... Figures 1-7The attenuator assembly 800 may include a housing or enclosure 102 having one or more walls or portions sealed together to form an internal cavity or chamber 106 that houses the transducer 924 and is separated from the surrounding environment 104. The transducer 824 may be a MEMS transducer configured to generate audible sound using ultrasonic modulation / demodulation techniques, which can be output to the surrounding environment 104, and more specifically, to the ears of a nearby user. To attenuate any unwanted ultrasonic frequencies, the transducer 824 may be coupled to an attenuator 808 configured to attenuate unwanted ultrasonic frequencies output by the transducer 824 before reaching the surrounding environment 104. Typically, the attenuator 808 may be connected to the sound output port of the transducer 824 through an opening 814 at its center and is configured to allow audible or desired sound output or otherwise leak to the surrounding environment 104 while attenuating or otherwise preventing the output of unwanted ultrasonic frequencies. For example, attenuator 808 may be formed by one or more walls 810, 816 connected to housing 102 and sealed to each other to define a hollow acoustic cavity 807. Transducer 824 may output sound wave 820 into acoustic cavity 807 of attenuator 808. Attenuator 808 may also include a plurality of openings 818A, 818B, 818C, 818D located between acoustic cavity 807 and surrounding environment 104 to output audible sound or audible sound waves to surrounding environment 104 (e.g., to the ears of a nearby user). Openings 818A-D may be formed at locations and / or sites along the walls 810 (e.g., top wall) of attenuator 808, which are selected to output or otherwise leak audible sound waves or desired sound waves to surrounding environment 104 through openings 818A-D, while attenuating or otherwise preventing undesirable ultrasonic frequencies from leaking through openings 818A-D, as previously discussed. Typically, similar to the previously discussed configuration, the openings 818A-D of the attenuator 808 can be formed at a location coinciding with the point of minimum pressure 820A of the sound wave 820 along the attenuator wall 810. In this respect, these ultrasonic frequencies will not leak through the openings 818A-D, while much lower audible tones will have a point of maximum pressure coinciding with the openings 818A-D, allowing the lower audible tones to leak from the openings 818A-D into the surrounding environment 104.

[0039] However, in some cases, residual ultrasonic frequencies may exist, which are found to still leak through openings 818A-D along with the desired lower-frequency audible tones. To attenuate these residual frequencies, the ultrasonic chip-level attenuator 836 can also be coupled to one or more of the attenuator output ports or openings to introduce a second stage of attenuation. For example, attenuator 808 can be configured to attenuate the ultrasonic carrier frequency as previously discussed, while chip-level attenuator 836 attenuates broadband ultrasonic frequencies or other frequencies in the ultrasonic frequency range different from the carrier frequency. Typically, the assembly may include an additional housing wall 830 attached to attenuator wall 810, which forms an additional acoustic cavity 809 around openings 818A-D and a neck portion 832 having an exit port or opening 834 to the surrounding environment 104. Chip-level attenuator 836 can be connected to the exit port or opening 834. Typically, the chip-level attenuator 836 may be formed from a chip or wafer 840 having a passage 842 extending completely through the wafer 840 and aligned with an opening 834 from the acoustic cavity 809. An attenuator cavity or resonator cavity 838 may branch or otherwise form outside the passage 842 and include an end to the passage 842 and extending into a closed volume or cavity formed within the wafer 840. Typically, in some aspects, the cavity 838 may be a Helmholtz resonator or a subwavelength tube (e.g., a half-wavelength tube, a quarter-wavelength tube) with one end to the passage 842 and extending into a closed air volume or cavity formed within the wafer 840. In this aspect, the cavity 838 can be used to attenuate any residual ultrasonic frequencies (e.g., broadband frequencies from 30 MHz to 1 MHz) that may leak into the passage 842 through openings 818A-D of the attenuator 808. It is anticipated that, in some respects, the addition of the chip-level attenuator 836 may produce at least an additional 10 dB to 20 dB of ultrasonic attenuation. It should also be understood that the secondary chip-level attenuator 836 may be coupled to any of the previously discussed attenuator assemblies 100, 300, 400, and 600 that may benefit from the additional ultrasonic attenuation.

[0040] Figures 9-10A cross-sectional side view illustrating another aspect of the attenuator assembly is shown. Attenuator assembly 900 may include similar aspects and operate in a manner similar to attenuator assemblies 100, 300, 500, 600, and 800 to attenuate ultrasonic frequencies while leaking audible tones. However, attenuator assembly 900 may also include an impedance tuning plate 922 coupled to attenuator 908 to selectively open / close attenuator aperture clusters 918A, 918B, 918C, and 918D to improve ultrasonic frequency attenuation. Typically, attenuator assembly 900 may include attenuator 908 having any of the geometries previously discussed (e.g., a hollow disk geometry) and coupled at its center to transducer 924 to radiate sound waves from the center of attenuator 908. For example, similar to... Figures 1-8The attenuator assembly 900 may include a housing or enclosure 102 having one or more walls or portions sealed together to form an internal cavity or chamber 106 that houses the transducer 924 and is separated from the surrounding environment 104. The transducer 924 may be a MEMS transducer configured to generate audible sound using ultrasonic modulation / demodulation techniques, which can be output to the surrounding environment 104, and more specifically, to the ears of a nearby user. To attenuate any unwanted ultrasonic frequencies, the transducer 924 may be coupled to an attenuator 908 configured to attenuate unwanted ultrasonic frequencies output by the transducer 924 before reaching the surrounding environment 104. Typically, the attenuator 908 may be connected to the transducer 924 through an opening 914 at its center and is configured to allow audible or desired sound output or otherwise leak to the surrounding environment 104 while attenuating or otherwise preventing the output of unwanted ultrasonic frequencies. For example, attenuator 908 may be formed by one or more walls 910, 916 connected to housing 102 and sealed to each other to define a hollow acoustic cavity 907. Transducer 924 may output sound wave 920 into acoustic cavity 907 of attenuator 908. Attenuator 908 may also include a cluster of openings 918A-D located between acoustic cavity 907 and surrounding environment 104 to output audible sound or audible sound waves to surrounding environment 104 (e.g., to the ears of a nearby user). In other words, each opening in openings 918A-D may consist of at least two or more smaller openings that together form a cluster or group of openings through which sound can pass. The opening clusters 918A-D may be formed at locations and / or sites along the wall 910 (e.g., the top wall) of the attenuator 908, chosen to allow audible or desired sound waves to leak or otherwise dissipate into the surrounding environment 104 through the opening clusters 918A-D, while attenuating or otherwise preventing undesirable ultrasonic frequencies from leaking through the opening clusters 918A-D, as previously discussed. Typically, similar to the previously discussed configuration, the opening clusters 918A-D of the attenuator 908 may be formed at locations along the attenuator wall 910 coinciding with the point of minimum pressure 920A of the sound wave 920. In this respect, these ultrasonic frequencies will not leak through (or only minimally leak through) the opening clusters 918A-D, while much lower audible tones will have a point of maximum pressure coinciding with the openings 918A-D, allowing lower audible tones to leak from the opening clusters 918A-D into the surrounding environment 104.

[0041] Additionally, component 900 may include an impedance tuning plate 922 to selectively and / or dynamically open / close the clusters of openings 918A-D to improve ultrasonic frequency attenuation. Typically, in some aspects, a protective filter or membrane 928 with micropores may be positioned above the openings 918A-D to protect the transducer 924 from environmental factors such as contaminants, water ingress, etc. The membrane 928 may increase impedance and thus alter or shift the position of the minimum pressure point 920A. This shift may cause some openings in the clusters of openings 918A-D to no longer be vertically aligned with or misaligned with the minimum pressure point 920A. To achieve realignment of the openings 918A-D with the minimum pressure point 920A, the impedance tuning plate 922 may be positioned above the clusters of openings 918A-D to selectively and dynamically open selected openings aligned with the minimum pressure point 920A and close openings misaligned with or misaligned with the minimum pressure point 920A. Typically, the impedance tuning plate 922 can be a plate or other planar structure having tuning ports 922A, 922B, 922C, and 922D respectively positioned above the opening clusters 918A-D. The plate 922 is further attached to an actuator 926 operable to translate and / or rotate the plate 922 relative to the attenuator 908 to open / close desired openings within the opening clusters 918A-D. For example, the actuator 926 can be a comb-like driver or a similar finger-like actuator, comprising a first static comb 926A having fingers arranged between the fingers of a second movable comb 926B attached to the plate 922. Applying a voltage to the actuator 908 can generate an electrostatic attraction between the combs 926A and 926B, pulling them together, which in turn causes the plate 922 to translate or rotate relative to the attenuator 908. This translation and / or rotation of plate 922 moves the position of plate openings 922A-D relative to opening clusters 918A-D, such that only the openings within the opening cluster aligned with the minimum pressure point 920A open, and the remaining openings in opening clusters 918A-D are covered by the plate and thus closed. Typically, as from... Figure 9 As can be seen, the plate openings 922A-D are shown aligned with one opening in each of the opening clusters 918A-D, which is vertically aligned with the minimum pressure point 920A of the ultrasonic frequency wave 920. The remaining openings in the opening clusters 918A-D are covered by the plate 922 and thus closed. When the minimum pressure point 920A is as... Figure 10 When moved as shown (e.g., to the right), actuator 926 moves plate 922 relative to opening clusters 918A-D to cover (e.g., close) openings no longer aligned with point 920A and open other openings within opening clusters 918A-D aligned with point 920A. Typically, as from... Figure 11As can be seen in the illustrated top view, the openings 922A-D of plate 922 can be circular openings, larger than each opening in the cluster of openings 918A-C, such that they are aligned with some of the circular openings in the clusters of openings 918A-D, while the remainder of the openings is covered by plate 922, as shown. Additionally, openings 922A-D are shown as being aligned with... Figure 11 The lower openings 918A-D shown are formed through the plate 922 in a similar annular pattern or arrangement. However, it is further contemplated that any other arrangement or shape of the plate openings 922A-D and / or opening clusters 918A-D as described herein may be used to selectively and dynamically open / close the opening clusters 918A-D as described herein.

[0042] Figure 12 Alternative tuner plates and their opening shapes and arrangements are illustrated. Typically, in this configuration, each opening in the cluster of openings 1218A-C formed in the attenuator (e.g., attenuator 908) may have a polygonal shape, such as a rectangular shape. Additionally, each opening in the cluster of openings 1222A, 1222B, 1222C formed in the tuner plate 1222 may also have a polygonal shape (e.g., a rectangular shape) and a larger size than each opening in the cluster of openings 1218A-C. In this respect, movement of the tuner plate 1222 relative to the openings 1218A-C in the attenuator may cause the openings 1222A-C to align with some openings in the cluster of openings 1218A-C, while other openings in the cluster are covered by the plate 1222 (e.g., closed), as shown. In another aspect, it is contemplated that a single large plate opening in the tuner plate can be used to selectively open / close desired openings in the cluster of openings.

[0043] Furthermore, it should be understood that, without the addition of acoustic impedance by membrane 928 and with the addition of impedance, the minimum pressure point of the ultrasonic frequency waveform (e.g., point 920A) is known and can be programmed into the system. The system also knows the positions of the openings in the tuning plate and attenuator, thus the system can determine which openings in the attenuator are aligned with the minimum pressure point and need to be opened, and which openings are misaligned at the minimum pressure point and therefore need to be closed. In this respect, the system can cause the actuator to move (e.g., rotate or translate) the tuning plate to dynamically tune the attenuation by opening / closing the desired attenuator openings based on the position of the minimum pressure point. Typically, in some aspects, the system can determine that at the minimum pressure point 920A in a first position, certain openings in the openings 918A-D of the attenuator 908 are aligned with point 920A, and the plate openings 922B-D are also aligned with openings 918A-D and point 920A, thus achieving maximum attenuation of the ultrasonic frequency. However, once the movement of the minimum pressure point 920A is detected, the system can determine that point 920A is in a different position or a second position that is no longer aligned with the attenuator openings 918A-D. The system can then apply voltage to the actuator to move plate 922 to another position where plate 922 covers some of the openings 918A-D that are now misaligned with point 920A, while opening any of the openings 918A-D that are now aligned with point 920A by aligning plate openings 922A-D with those openings.

[0044] In another aspect, it is anticipated that the impedance tuning plates 922 and / or 1222 and the membrane 928 can be manufactured as a single unit, such that the membrane 928 is connected to the plates 922 and 1222. For example, the membrane 928 may be positioned above and attached to the plates 922 and 1222. In this respect, the tuning plates 922 and / or 1222 can provide the additional advantage of serving as structural support for the membrane 928. Typically, the membrane 928 may be made of a flexible material or have a minimum compliance, allowing it to bend or move in response to certain environmental pressures (e.g., water pressure), which could cause it to unintentionally obstruct the attenuator opening below. However, the presence of the plate 922 between the membrane 928 and the attenuator provides support for the membrane 928 and prevents it from bending or moving in a manner that could obstruct the attenuator opening.

[0045] See now Figure 13 , Figure 13 A block diagram illustrating one aspect of an electronic device in which the previously discussed loudspeaker can be implemented is shown. For example... Figure 13 As shown, device 1300 may include storage device 1302. Storage device 1302 may include one or more different types of storage devices, such as hard disk drive storage devices, non-volatile memory (e.g., flash memory or other electrically programmable read-only memory), volatile memory (e.g., battery-based static or dynamic random access memory), etc.

[0046] Processing circuitry 1304 can be used to control the operation of device 1300. Processing circuitry 1304 may be based on a processor, such as a microprocessor and other suitable integrated circuits. Using a suitable arrangement, processing circuitry 1304 and storage device 1302 can be used to run software on device 1300, such as internet browsing applications, Voice over Internet Protocol (VoIP) telephone calling applications, email applications, media playback applications, operating system functions, etc. Processing circuitry 1304 and storage device 1302 can be used to implement suitable communication protocols. Communication protocols that can be implemented using processing circuitry 1304 and storage device 1302 include Internet Protocol, wireless LAN protocols (e.g., IEEE 802.11 protocol – sometimes called Wi-Fi). ® Protocols used for other short-range wireless communication links, such as Bluetooth. ® Protocols, protocols used to process 3G or 4G communication services (e.g., using wideband code division multiple access technology), 2G cellular telephone communication protocols, etc.

[0047] To minimize power consumption, processing circuitry 1304 may include power management circuitry for implementing power management functions. For example, processing circuitry 1304 may be used to adjust the gain settings of amplifiers (e.g., RF power amplifier circuitry) on device 1300. Processing circuitry 1304 may also be used to adjust the power supply voltage supplied to portions of the circuitry on device 1300. For example, a higher DC power supply voltage may be supplied to active circuitry, and a lower DC power supply voltage may be supplied to less active or inactive circuitry. If desired, processing circuitry 1304 may be used to implement control schemes in which the power amplifier circuitry is adjusted to accommodate transmission power level requests received from the wireless network.

[0048] Input / output device 1306 can be used to allow data to be supplied to device 1300 and to be supplied from device 1300 to external devices. Display screens, microphone acoustic ports, speaker acoustic ports, and docking ports are examples of input / output device 1306. For example, input / output device 1306 may include user input / output device 1308, such as buttons, touchscreens, joysticks, click wheels, scroll wheels, touchpads, keypads, keyboards, microphones, cameras, etc. Users can provide commands through user input device 1308 to control the operation of device 1300. Display and audio device 1310 may include a liquid crystal display (LCD) screen or other screen, light-emitting diodes (LEDs), and other components that present visual information and status data. Display and audio device 1310 may also include audio equipment, such as speakers and other devices for generating sound. Display and audio device 1310 may include audio-visual interface equipment, such as jacks and other connectors for external headphones and monitors.

[0049] Wireless communication device 1312 may include communication circuitry, such as radio frequency (RF) transceiver circuitry formed by one or more integrated circuits, power amplifier circuitry, passive RF components, an antenna, and other circuitry for processing RF wireless signals. The wireless signals may also be transmitted using light (e.g., using infrared communication). Typically, in the case of a speaker acoustic port, the speaker may be associated with the port and communicate with an RF antenna for transmitting signals from a remote user to the speaker.

[0050] return Figure 13 Device 1300 can communicate with external devices such as accessory 1314, computing equipment 1316, and wireless network 1318, as shown in paths 1320 and 1322. Path 1320 may include wired and wireless paths. Path 1322 may be a wireless path. Accessory 1314 may include headphones (e.g., wireless cellular headphones or audio headsets) and audio-visual equipment (e.g., wireless speakers, game controllers, or other equipment that receives and plays audio and video content), peripheral devices such as wireless printers or cameras, etc.

[0051] Computing device 1316 can be any suitable computer. In a suitable arrangement, computing device 1316 is a computer with an associated wireless access point (router) or internal or external wireless network card that establishes a wireless connection with device 1300. The computer can be a server (e.g., an internet server), a local area network computer with or without internet access, a user's own personal computer, a peer-to-peer device (e.g., another portable electronic device), or any other suitable computing device.

[0052] Wireless network 1318 may include any suitable network equipment, such as cellular phone base stations, cellular towers, wireless data networks, computers associated with the wireless network, etc. For example, wireless network 1318 may include network management equipment that monitors the wireless signal strength of wireless mobile phones (cellular phones, handheld computing devices, etc.) communicating with network 1318.

[0053] While certain aspects have been described and illustrated in the accompanying drawings, it should be understood that such aspects are merely illustrative of the broad disclosure and not limiting, and that this disclosure is not limited to the specific structures and arrangements shown and described, as various other modifications will be apparent to those skilled in the art. Therefore, the description is to be regarded as exemplary and not restrictive. For example, although a loudspeaker is specifically disclosed herein, the attenuator disclosed herein can be used with other types of transducers (e.g., microphones). Furthermore, although portable electronic devices such as wearable devices including smart glasses or other head-mounted devices are described herein, any of the attenuator and transducer configurations previously discussed can be implemented in other devices such as earbuds, headphones, mobile communication devices, tablets, personal computers, laptops, notebook computers, etc. Additionally, to assist the Patent Office and any reader of any patent granted under this application in interpreting the appended claims, the applicant wishes to indicate that they do not intend any appended claims or claim elements to reference 35 USC112(f) unless “component for…” or “step for…” is expressly used in a particular claim.

Claims

1. A transducer attenuator assembly, the transducer attenuator assembly comprising: A housing that defines a acoustic cavity coupled to the sound output port of a transducer, the transducer being operable to generate audible frequencies from ultrasonic frequencies; and Multiple openings are formed through the housing to acoustically connect the acoustic cavity to the surrounding environment, and the multiple openings are arranged to attenuate ultrasonic waves and leak audible sound waves output by the transducer into the acoustic cavity.

2. The transducer attenuator assembly according to claim 1, wherein, At least one of the plurality of openings is aligned with the point of minimum pressure of the ultrasonic wave.

3. The transducer attenuator assembly according to claim 1, wherein, The housing includes a rectangular tube having an end connected to the sound output port of the transducer, and the plurality of openings are formed through the side of the rectangular tube at a position aligned with the point of minimum pressure of the longitudinal standing wave formed by the ultrasonic waves.

4. The transducer attenuator assembly according to claim 1, wherein, The housing includes a disk having a first side and a second side, the first side including a central opening acoustically connected to the sound output port of the transducer, the second side being arranged parallel to the first side, and the plurality of openings being formed through the second side.

5. The transducer attenuator assembly according to claim 4, wherein, The ultrasonic waves form a meridional standing wave within the acoustic cavity, and each of the plurality of openings is aligned with the point of minimum pressure of the meridional standing wave.

6. The transducer attenuator assembly according to claim 4, wherein, The plurality of openings are arranged in a concentric ring pattern along the second side of the disk.

7. The transducer attenuator assembly according to claim 1, wherein, The housing includes a cone having a first side and a second side. The first side includes a vertex with a central opening connected to the sound output port of the transducer. The second side is arranged parallel to the first side, and a plurality of openings are formed through the second side.

8. The transducer attenuator assembly according to claim 1, wherein, At least one of the plurality of openings defines a main channel extending from the acoustic cavity to the surrounding environment, and an auxiliary channel extending from the sidewall of the main channel, the auxiliary channel being tuned to attenuate the ultrasonic waves.

9. The transducer attenuator assembly according to claim 1, wherein the transducer attenuator assembly further comprises: A housing, the housing being coupled to the side of the outer shell through which the plurality of openings are formed, and the housing having a port to the surrounding environment; And a chip-level attenuator, which is acoustically coupled to the port to attenuate residual ultrasonic frequency waves within the housing.

10. The transducer attenuator assembly according to claim 1, wherein, At least one of the plurality of openings comprises an opening cluster.

11. The transducer attenuator assembly of claim 10, further comprising a protective membrane and a movable tuning plate disposed above the opening cluster, the movable tuning plate being operable to open an opening within the opening cluster aligned with the minimum pressure point of the ultrasonic wave and close an opening within the opening cluster misaligned with the minimum pressure point.

12. A portable electronic device, the portable electronic device comprising: A device housing having a housing wall defining an internal chamber that is isolated from the surrounding environment; A transducer attenuator is coupled to the device housing and defines a acoustic cavity within the internal chamber, the acoustic cavity being coupled to the sound output port of the transducer, and the transducer being operable to generate audible sound waves from ultrasound. and Multiple openings are formed through the transducer attenuator to acoustically connect the acoustic cavity to the surrounding environment, and at least one of the multiple openings is aligned with the point of minimum pressure of the ultrasonic waves output from the transducer to the acoustic cavity.

13. The portable electronic device according to claim 12, wherein, The plurality of openings are aligned with the plurality of points of minimum pressure of the ultrasonic waves to attenuate the ultrasonic waves and to leak the audible sound waves output by the transducer into the acoustic cavity.

14. The portable electronic device according to claim 12, wherein, The transducer attenuator includes a sealed-end transmission line having a length that is an integer multiple of the ultrasonic wave output by the transducer, and the plurality of openings are arranged along the length of the transmission line such that at least one opening is aligned with the point of minimum pressure of the ultrasonic wave.

15. The portable electronic device according to claim 12, wherein, The transducer attenuator includes a hollow disk having a first side and a second side. The first side includes a central opening connected to the sound output port of the transducer. The second side is arranged parallel to the first side, and the plurality of openings are formed through the second side.

16. The portable electronic device according to claim 15, wherein, The ultrasonic waves form a meridional standing wave within the acoustic cavity, and each of the plurality of openings is aligned with the point of minimum pressure of the meridional standing wave.

17. The portable electronic device according to claim 12, wherein, The transducer attenuator includes a cone having a first side and a second side. The first side includes a vertex with a central opening connected to the sound output port of the transducer. The second side is arranged parallel to the first side, and a plurality of openings are formed through the second side.

18. The portable electronic device according to claim 12, wherein, At least one of the plurality of openings defines a main channel extending from the acoustic cavity to the surrounding environment, and an auxiliary channel extending from the sidewall of the main channel, the auxiliary channel being tuned to attenuate the ultrasonic waves.

19. The portable electronic device according to claim 12, further comprising: The housing is coupled to the side of the transducer attenuator through which the plurality of openings are formed, and the housing has a port to the surrounding environment; And a chip-level attenuator, which is acoustically coupled to the port to attenuate residual ultrasonic waves within the housing.

20. The portable electronic device of claim 12, wherein the device housing includes a wearable device housing.

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