Earphone low-frequency compensation method and open earphone

Abstract

The invention relates to the technical field of electronics, in particular to an earphone low-frequency compensation method and an open earphone, and the earphone low-frequency compensation method comprises the steps: obtaining a low-frequency band signal in an audio signal based on the audio signal inputted into a sound production unit of the open earphone; generating a low-frequency vibration signal according to the low-frequency band signal; and inputting the low-frequency vibration signal to a vibration unit of the open earphone. The invention mainly aims to provide a low-frequency compensation method for an earphone, and aims to remarkably improve low-frequency experience through touch compensation while ensuring that an open type earphone keeps comfort.

Description

Technical Field

[0001] This invention relates to the field of acoustic technology, and in particular to a method for low-frequency compensation of headphones and an open-back headphone. Background Technology

[0002] Low-frequency sound waves have longer wavelengths and require a closed space to create a good low-frequency sound pressure level.

[0003] For open-back headphones, because the earbuds do not fit snugly into the ear canal / auricle, sound leakage occurs through gaps. When playing low-frequency audio, these gaps allow low-frequency audio to escape, resulting in a loss of low-frequency sound pressure. This loss of sound pressure directly affects the listening experience, manifesting as reduced bass drum impact, blurred bass lines, and an overall lack of sufficient penetration and impact in the low-frequency sound. The headphones fail to reproduce the original low-frequency details and dynamic range of the audio signal, ultimately impacting the overall audio playback quality. Summary of the Invention

[0004] The main objective of this invention is to provide a low-frequency compensation method for headphones, which aims to ensure that open-back headphones significantly improve the low-frequency experience through vibration tactile compensation while maintaining comfort.

[0005] To achieve the above objectives, the open-back headphones include a vibration unit and a sound-generating unit, the sound-generating unit being used to play audio signals, and the vibration unit being used to contact the ear. The low-frequency compensation method for the headphones includes: Based on the audio signal input to the sound unit of the open-back headphones, the low-frequency band signal in the audio signal is obtained; Based on the low-frequency band signal, a low-frequency vibration signal is generated; The low-frequency vibration signal is input to the vibration unit of the open-back headphones.

[0006] In one embodiment of the present invention, the step of generating a low-frequency vibration signal based on the low-frequency band signal includes: Based on the low-frequency band signal, a low-frequency time domain signal and a low-frequency frequency signal are obtained; The low-frequency vibration signal is generated based on the low-frequency time-domain signal and the low-frequency frequency signal.

[0007] In one embodiment of the present invention, the step of obtaining a low-frequency time-domain signal based on the low-frequency band signal includes: Based on the low-frequency band signal, full-wave rectification is performed to obtain a rectified signal; Based on a preset cutoff frequency, the rectified signal is subjected to low-pass filtering to obtain an envelope signal; The low-frequency time-domain signal is obtained based on the envelope signal.

[0008] In one embodiment of the present invention, the step of obtaining a low-frequency signal based on the low-frequency band signal includes: Based on the low-frequency band signal, perform Fast Fourier Transform processing to obtain the frequency domain spectrum; Based on a preset frequency band range, the frequency domain spectrum is filtered to obtain the target frequency band signal; The target frequency band signal is subjected to inverse Fourier transform processing to obtain the low frequency signal.

[0009] In one embodiment of the present invention, the step of generating the low-frequency vibration signal based on the low-frequency time-domain signal and the low-frequency frequency signal further includes: Based on the low-frequency signal, determine the first gain signal corresponding to each frequency in the low-frequency signal; The low-frequency vibration signal is generated based on the low-frequency time-domain signal, the low-frequency frequency signal, and the first gain signal.

[0010] In one embodiment of the present invention, after inputting the low-frequency vibration signal to the vibration unit of the open-back headphone, the method further includes: Determine the environmental noise intensity corresponding to the environmental noise signal based on the environmental noise signal; The second gain signal is determined based on the ambient noise intensity. An environmental modulation signal is obtained based on the low-frequency vibration signal and the second gain signal; The environmental modulation signal is input to the vibration unit of the open-back headphones.

[0011] In one embodiment of the present invention, the method further includes: Receive vibration drive commands from the outside; A vibration drive signal is generated according to the vibration drive command; The vibration drive signal is input to the vibration unit of the open-back headphones.

[0012] In one embodiment of the present invention, the method further includes: Obtain user operation commands; Based on the user's operation instructions, an operation confirmation vibration signal is generated; The operation confirmation vibration signal is input to the vibration unit of the open-back headphones.

[0013] In one embodiment of the present invention, the audio signal is a dual-channel audio signal, and the vibration unit includes a left ear vibration unit and a right ear vibration unit; The step of obtaining the low-frequency band signal from the audio signal input to the sound unit of the open-back headphones includes: Based on the dual-channel audio signal, the low-frequency band signal of the left channel and the low-frequency band signal of the right channel are obtained; The step of generating a low-frequency vibration signal based on the low-frequency band signal includes: Based on the low-frequency band signal of the left channel, the original vibration signal of the left channel is generated; Based on the low-frequency band signal of the right channel, the original vibration signal of the right channel is generated; Extract the amplitude characteristics of the original vibration signal of the left channel and the original vibration signal of the right channel at the same time. Based on the amplitude characteristics of the original vibration signal of the right channel from the original vibration signal of the left channel, the left channel allocation coefficient and the right channel allocation coefficient are obtained. A first low-frequency vibration signal is generated based on the original vibration signal of the left channel and the allocation coefficient of the left channel; A second low-frequency vibration signal is generated based on the original vibration signal of the right channel and the allocation coefficient of the right channel; The step of inputting the low-frequency vibration signal to the vibration unit of the open-back headphone includes: The first low-frequency vibration signal is input to the left ear vibration unit; The second low-frequency vibration signal is input to the right ear vibration unit.

[0014] The present invention also proposes an open-back headphone for implementing the headphone low-frequency compensation method described in any of the above-mentioned methods, wherein the open-back headphone includes a signal processing module, a vibration unit, and a sound-generating unit; The signal processing module is configured to output a low-frequency vibration signal corresponding to the audio signal to be played. The vibration unit is configured to receive the low-frequency vibration signal; The sound unit is configured to receive the audio signal to be played.

[0015] In this technical solution, the headphone low-frequency compensation method utilizes a technique based on generating tactile vibrations from audio signals. This addresses the technical problems of insufficient low-frequency sound pressure and a lack of impact in bass due to sound leakage in open-back headphones. Specifically, firstly, low-frequency bands are extracted from the original playback signal input to the open-back headphone's driver unit. This ensures that the compensated low-frequency signal accurately corresponds to the low-frequency components of the original audio, avoiding deviation from the target frequency band. Subsequently, a suitable low-frequency vibration signal is generated based on the extracted low-frequency band, ensuring that the frequency, amplitude, and other characteristics of the vibration signal match the low-frequency audio characteristics to be compensated, guaranteeing targeted compensation. Finally, a vibration unit designed for contact with the ear transmits the low-frequency vibration signal directly to the human tactile nerves through the ear skin via mechanical vibration. This bypasses the drawback of open-back headphones, which rely on acoustic channels for low-frequency transmission but suffer from sound energy dissipation due to leakage. Through the process of "audio signal extraction to vibration signal generation to tactile contact transmission," the low-frequency enhancement logic of "vibration tactile compensation for hearing" is achieved, enabling low-frequency perception to be transmitted without relying on a closed space. Because the physical vibration generated by the vibrating unit directly compensates for the loss of low-frequency sensation due to acoustic leakage, through the fusion of auditory and tactile senses, even if the low-frequency audio played by the open-back headphones cannot reach the ears, users can still feel the vibration corresponding to the low-frequency audio through tactile effects, thereby achieving the effect of bass enhancement and improving the user's listening experience. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the first process of the headphone low-frequency compensation method provided by the present invention; Figure 2 This is a schematic diagram of the second process of the headphone low-frequency compensation method provided by the present invention; Figure 3 This is a schematic diagram of the third process of the headphone low-frequency compensation method provided by the present invention; Figure 4 This is a schematic diagram of the fourth process of the headphone low-frequency compensation method provided by the present invention; Figure 5 This is a schematic diagram of the fifth step in the headphone low-frequency compensation method provided by the present invention; Figure 6 This is a schematic diagram of the sixth process of the headphone low-frequency compensation method provided by the present invention; Figure 7This is a schematic diagram of the seventh process of the headphone low-frequency compensation method provided by the present invention; Figure 8 This is a schematic diagram of the eighth process of the headphone low-frequency compensation method provided by the present invention; Figure 9 This is a schematic diagram of the ninth step in the headphone low-frequency compensation method provided by the present invention. Figure 10 This is a schematic diagram of an embodiment of the open-back headphone provided by the present invention.

[0018] Explanation of icon numbers: 100. Open-back headphones; 10. Sound unit; 20. Vibration unit.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0022] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] The main objective of this invention is to provide a low-frequency compensation method for headphones, which aims to ensure that open-back headphones 100 significantly improve the low-frequency experience through vibration tactile compensation while maintaining comfort.

[0024] To achieve the above objectives, the open-back headphone 100 includes a vibration unit 20 and a sound-generating unit 10. The sound-generating unit 10 is used to play audio signals, and the vibration unit 20 is used to contact the ear. Please refer to [link to relevant documentation]. Figure 1 Low-frequency compensation methods for headphones include: S10: Based on the audio signal from the sound-emitting unit 10 of the input open-back headphone 100, acquire the low-frequency band signal in the audio signal; S20: Generates low-frequency vibration signals based on low-frequency band signals; S30: Inputs low-frequency vibration signals to the vibration unit 20 of the open-back headphone 100.

[0025] This invention provides a low-frequency compensation method for headphones, aiming to ensure that open-back headphones 100, while retaining their inherent comfort, significantly enhance the user's low-frequency listening experience through a vibration-tactile compensation mechanism. Open-back headphones 100 are audio devices that do not fit tightly against the user's ear canal or auricle. Common types include semi-in-ear headphones, open-back headphones, ear-hook open-back headphones 100, and neckband open-back headphones 100, etc. There is a physical sound leakage gap between the earbud portion of open-back headphones 100 and the ear canal / auricle, preventing the formation of a closed acoustic cavity within the ear. This is the fundamental reason why low-frequency sound pressure easily dissipates and the bass effect is weak. To implement the low-frequency compensation method for headphones proposed in this invention, the open-back headphones 100 include two core driving components: a sound-generating unit 10 and a vibration unit 20. It should be noted that the vibration unit 20 is different from the sound-generating unit 10. The sound-generating unit 10 is a traditional electroacoustic transducer, which converts electrical signals into sound waves in the air to play audible audio. The vibration unit 20 is a specific tactile feedback device, which generates physical mechanical vibration after receiving an electrical signal and transmits this vibration to the user by contacting the skin of the ear, such as the auricle or external auditory canal, thereby simulating a low-frequency "feel" as a supplement to the acoustic hearing experience. It can be understood that the vibration unit 20 can be a micro rotor motor or a micro linear motor, which is not limited here.

[0026] In step 10, the "audio signal" refers to the original electrical signal input to the headphone speaker unit 10, intended to be converted into sound, which contains information across the entire frequency range from high to low frequencies. For targeted low-frequency compensation, the processor of the open-back headphone 100 first separates specific low-frequency components from the full frequency range of the audio signal. Specifically, it extracts a preset frequency range, such as a "low-frequency band signal" from the original audio signal, through high-pass, low-pass, or band-pass filters. The determination of this preset range can be based on the characteristics of human hearing, the mechanism of human tactile perception, and the acoustic defects of the open-back headphones 100. For example, the lower limit of low frequency that the human ear can perceive is about 20Hz. Sound waves below this frequency are difficult to form an effective listening experience. Therefore, the lower limit of the cutoff range is set at or near 20Hz. Considering that the frequency band in which human skin is most sensitive to mechanical vibration is mainly concentrated below 150Hz, and the frequency band in which the sound pressure of the open-back headphones 100 is severely attenuated due to physical sound leakage is usually within 200Hz, and combined with the optimal operating efficiency frequency of the vibration unit 20 (such as a linear resonator), the upper limit of the cutoff range is optimized and set at around 150Hz. Based on this, a typical preset low frequency cutoff range can be determined to be 20Hz to 150Hz. In actual processing, this step uses a digital filter (such as a bandpass filter or a lowpass filter) to process the input audio signal in real time, allowing only signal components within the preset frequency band to pass through, thereby extracting a pure "low-frequency band signal" designed to drive the vibration unit 20 for tactile compensation, laying a precise signal foundation for the subsequent generation of synchronized and delicate low-frequency vibrations.

[0027] Step S20 is a signal processing and conversion step. The "low-frequency vibration signal" generated by the processor is an electrical signal specifically designed to drive the vibration unit 20, and its characteristics (such as waveform, amplitude, and frequency) need to match tactile perception. For example, envelope extraction can be performed on the signal to capture the rhythm and intensity (transient) of low frequencies, or frequency weighting can be applied to highlight the frequency points most sensitive to tactile perception, while suppressing frequencies that may cause discomfort or ineffective vibration. In addition, dynamic range compression is involved to ensure that the vibration intensity can be perceived at weak bass frequencies, but not so intensely as to cause discomfort at strong bass frequencies.

[0028] Step S30 is the final energy conversion and effect realization stage. After receiving the low-frequency vibration signal, the vibration unit 20 will generate corresponding mechanical vibration according to the characteristics of the signal. Since the vibration unit 20 is in direct contact with the user's ear skin, these physical vibrations will be transmitted through the bones and skin and perceived by the user's tactile nervous system. Because the audio playback of the sound unit 10 and the vibration of the vibration unit 20 occur simultaneously, the tactile vibration perception can be combined with the audible low-frequency sound that may be attenuated due to sound leakage and played simultaneously by the sound unit 10, forming a complete, powerful and impactful low-frequency experience in the brain. Thus, without changing the physical structure of the open-back headphones 100, without sacrificing wearing comfort and external transparency, the tactile vibration compensates for the acoustic low-frequency loss caused by sound leakage.

[0029] In one embodiment, when a user wears an open-back headphone 100 that applies the headphone low-frequency compensation method proposed in this invention, when the audio signal includes a low-frequency segment interwoven with bass drum and bass, the processor built into the headphone accurately extracts the low-frequency band signal representing the bass drum strikes and bass string plucking sound waves from the complete audio signal input to the sound unit 10, and through a bandpass filter preset to 20Hz to 150Hz.

[0030] Subsequently, based on the characteristics of this low-frequency signal, the processor captures the envelope of the signal strength through full-wave rectification and low-pass filtering. This envelope precisely corresponds to the impact moment of each drumbeat and the continuous attenuation of the bass sound. This envelope signal is then multiplied by an optimized gain coefficient to finally synthesize a low-frequency vibration signal that can reflect the intensity of the low-frequency rhythm and whose voltage and waveform can efficiently drive the micro vibrator.

[0031] Finally, the low-frequency vibration signal is transmitted by the processor to the vibration unit 20 that is in contact with the user's ear. The vibration unit 20 immediately converts the electrical signal into precise physical vibration. Thus, while the user hears the low-frequency melody through the sound unit 10, their auricle skin clearly feels a strong and layered vibration sensation that is completely synchronized with the rhythm of the bass drum and bass. Through vibration tactile compensation, a full and complete bass listening experience is achieved.

[0032] In this technical solution, the headphone low-frequency compensation method utilizes a technique based on generating tactile vibrations from audio signals. This addresses the technical problem of insufficient low-frequency sound pressure and a lack of impact in bass due to sound leakage in open-back headphones 100. Specifically, firstly, low-frequency bands are extracted from the original playback signal input to the sound-generating unit 10 of the open-back headphones 100, ensuring that the compensated low-frequency signal accurately corresponds to the low-frequency components of the original audio, avoiding deviation from the target frequency band. Subsequently, a suitable low-frequency vibration signal is generated based on the extracted low-frequency band, ensuring that the frequency, amplitude, and other characteristics of the vibration signal match the low-frequency audio characteristics to be compensated, guaranteeing the targeted nature of the compensation. Finally, using the vibration unit 20 "for contact with the human ear," the low-frequency vibration signal is transmitted directly to the human tactile nerves through the ear skin in the form of mechanical vibration, bypassing the defect of open-back headphones 100 that relies on auditory transmission through the sound channel but suffers from sound energy dissipation due to sound leakage. Through the process of "audio signal extraction to vibration signal generation to tactile contact transmission," the low-frequency enhancement logic of "vibration tactile compensation for hearing" is realized, enabling the transmission of low-frequency perception without relying on a closed space. Because the physical vibration generated by the vibration unit 20 directly compensates for the loss of low-frequency sensation due to acoustic leakage, through the fusion of auditory and tactile senses, even if the low-frequency audio played by the open-back headphones 100 cannot reach the ears, the user can still feel the vibration corresponding to the low-frequency audio through tactile effects, thereby achieving the effect of bass enhancement and improving the user's listening experience.

[0033] In one embodiment of the present invention, please refer to Figure 2 Step 20 includes: S210: Obtain low-frequency time-domain signals and low-frequency frequency signals based on low-frequency band signals; S220: Generates low-frequency vibration signals based on low-frequency time-domain signals and low-frequency frequency signals.

[0034] Step 210 involves analyzing and decomposing the low-frequency band signal extracted in step 10, which falls within a preset range. Using digital signal processing algorithms such as envelope extraction, Fourier transform, and short-time Fourier transform, low-frequency time-domain signals and low-frequency frequency signals reflecting different dimensions of characteristics are separated from the single low-frequency band electrical signal. The low-frequency time-domain signal refers to a signal form that records the dynamic changes in the amplitude of the low-frequency band signal over time, with time as the axis. It can accurately capture the transient characteristics of low-frequency audio, such as the impact moment of bass drum beats and the continuous decay process of bass sounds, directly corresponding to the low-frequency listening experience. Rhythm and intensity changes; low-frequency signals refer to the signal form that reflects the distribution and corresponding intensity of each frequency component in the low-frequency band signal. It can clearly present the frequency band distribution characteristics of low-frequency audio, such as the proportion of different low-frequency components and the peak frequency position, in order to adapt to the matching requirements of the human tactile sensitive frequency band and the working frequency of the vibration unit 20; relying on the processor of the open-back headphone 100 to convert and analyze the low-frequency band signal, it provides comprehensive and accurate parameter support for the subsequent generation of vibration signals by integrating multi-dimensional features, avoiding the lack of detail in the vibration effect or deviation from the original audio due to a single-dimensional signal.

[0035] Step 220 is the low-frequency compensation signal synthesis stage. It integrates the dual characteristics of low-frequency time-domain signals and low-frequency frequency signals, generating a low-frequency vibration signal adapted to the vibration unit 20 and tactile perception through multi-parameter fusion processing. Specifically, the processor of the open-back headphone 100 first extracts the envelope based on the amplitude variation characteristics of the low-frequency time-domain signal, such as capturing the signal intensity envelope through full-wave rectification and low-pass filtering, ensuring that the intensity variation of the vibration signal is completely synchronized with the transient rhythm of the original low-frequency audio, such as drumbeats and note decay. Then, it combines the frequency band distribution characteristics of the low-frequency signal with tactile sensitivity... Frequency-weighted enhancement is performed on frequency bands (such as below 150Hz) while suppressing frequency components that exceed the operating range of the vibration unit 20 or are prone to causing discomfort. Then, the vibration intensity is balanced by dynamic range compression to avoid insufficient perception of weak bass and excessive intensity of strong bass. The processed signal is multiplied by the optimized gain coefficient to accurately match the signal voltage, waveform and operating parameters of the vibration unit 20 (such as a miniature linear resonator). Finally, a low-frequency vibration signal with rhythm synchronization, tactile adaptability and driving effectiveness is generated, laying the foundation for subsequent vibration transmission and low-frequency compensation effects.

[0036] In one embodiment, please refer to Figure 3 Step 210 includes; S2110: Perform full-wave rectification processing based on the low-frequency band signal to obtain a rectified signal; S2120: Based on a preset cutoff frequency, perform low-pass filtering on the rectified signal to obtain the envelope signal; S2130: Obtain low-frequency time-domain signals based on envelope signals.

[0037] Specifically, step 2110 is the pre-processing stage for low-frequency time-domain signal extraction. Its core is to perform full-wave rectification on the selected low-frequency band signal. Through the rectifier circuit or digital signal processing algorithm in the headphone's built-in processor, all negative amplitude components in the signal are inverted and converted to positive components, ultimately obtaining a unidirectional electrical signal (i.e., a rectified signal) that retains only positive amplitude changes and has no negative fluctuations. "Full-wave rectification" refers to a processing method that converts both the positive and negative half-cycles of an AC signal into signals of the same direction. This differs from half-wave rectification, which only retains one half-cycle. Its core advantage lies in completely preserving all amplitude change information of the low-frequency band signal, avoiding distortion in subsequent envelope extraction due to signal loss. The core characteristic of the "rectified signal" is that its amplitude change trend is completely consistent with the amplitude change trend of the original low-frequency band signal. This not only eliminates the difference in positive and negative polarities but also transforms the "bidirectional fluctuations" of the original low-frequency signal into a "unidirectional trend," laying the foundation for subsequent filtering of high-frequency ripples and extraction of the envelope signal reflecting the rhythm and intensity of the low frequencies.

[0038] Step 2120 is the core filtering and trend extraction stage of low-frequency time domain signal extraction. The core is to perform low-pass filtering on the rectified signal based on full-wave rectification and using the preset cutoff frequency as the screening criterion. The high-frequency ripple components generated by rectification in the rectified signal are filtered out by digital filters, and the smooth signal (i.e. envelope signal) that reflects the overall amplitude change trend of the signal is retained. The "preset cutoff frequency" is a frequency threshold preset based on the characteristics of human tactile perception and the requirements for low-frequency audio rhythm recognition, such as 10Hz-50Hz, for example, 30Hz. This range can filter high-frequency interference introduced by rectification while fully preserving the rhythmic change cycle of low-frequency audio such as bass drum beats and bass string plucking. "Low-pass filtering" refers to a signal processing method that only allows signal components with frequencies lower than the preset cutoff frequency to pass through, while blocking high-frequency interference components with frequencies higher than that frequency from being transmitted. "Envelope signal" refers to a signal that smoothly follows the overall trend of the amplitude change of the rectified signal. Its waveform can accurately reflect the dynamic changes in the intensity of the original low-frequency band signal (such as the amplitude peak when the drum beats, and the amplitude decay process when the note continues). It is equivalent to the "rhythm contour signal" after stripping away high-frequency details, providing the core feature carrier for subsequent acquisition of low-frequency time-domain signals.

[0039] S2130 is the final stage for determining the low-frequency time-domain signal. The core of this stage is to directly use the envelope signal, obtained after full-wave rectification and low-pass filtering, as the core signal reflecting the time-domain characteristics of the low-frequency band signal—the low-frequency time-domain signal. Alternatively, the low-frequency time-domain signal can be determined by performing fine-tuning processes such as gain calibration and baseline adjustment on the envelope signal (ensuring the signal amplitude matches the driving requirements of the subsequent vibration unit 20). The "low-frequency time-domain signal" refers to a signal form that visually reflects the rhythm and intensity changes of low-frequency audio, with time as the horizontal axis and signal amplitude as the vertical axis. Its core function is to provide time-domain parameter support for the subsequent S220 step, ensuring that the generated low-frequency vibration signal accurately matches the transient impact, continuous decay, and other time-dimensional characteristics of the original low-frequency audio, allowing the user to perceive a vibration effect completely synchronized with the audio rhythm through touch.

[0040] In one embodiment, please refer to Figure 4 Step 210 includes: S2140: Perform Fast Fourier Transform processing on the low-frequency band signal to obtain the frequency domain spectrum; S2150: Based on a preset frequency band range, perform filtering on the frequency domain spectrum to obtain the target frequency band signal; S2160: Perform inverse Fourier transform processing on the target frequency band signal to obtain the low-frequency signal.

[0041] Step S2140 performs Fast Fourier Transform (FFT) processing on the selected low-frequency band signal. The digital signal processing module in the built-in processor of the open-back headphone 100 calls an efficient frequency domain conversion algorithm to convert the time domain signal, which originally only reflects the amplitude change over time, into a frequency domain spectrum with frequency as the horizontal axis and signal strength (such as amplitude and power) as the vertical axis. The "Fast Fourier Transform Processing" refers to a highly efficient digital signal processing algorithm optimized based on the Fourier transform principle. Compared with the traditional Fourier transform, its core advantage lies in its faster processing speed, which can meet the real-time requirements of headphone audio processing and ensure synchronous progress with the time-domain signal extraction process of S2110-S2130. The "Frequency Domain Spectrum" visually presents the distribution and corresponding intensity of each single frequency component in the low-frequency band signal (e.g., the intensity of the 50Hz component, the intensity of the 100Hz component, etc.). Its function is to decompose the "time dimension change" of the original low-frequency band signal into "frequency dimension composition", providing a visual and quantifiable analytical basis for subsequent accurate selection of target frequency components that are compatible with the working characteristics of the tactile sensing and vibration unit 20.

[0042] S2150 is the precise screening stage for low-frequency signal extraction. Its core is to perform frequency domain filtering on the frequency domain spectrum based on the preset frequency band range as the screening threshold. The digital bandpass filtering algorithm retains the frequency components in the spectrum that are within the preset frequency band range and removes invalid frequency components that are outside the range (such as excessively low frequency, excessively high frequency, or interference frequencies). Finally, a frequency domain signal containing only the target frequency components (i.e., the target frequency band signal) is obtained. The "preset frequency band range" is a frequency range determined by comprehensively considering the sensitive characteristics of human tactile perception (e.g., below 150Hz is the tactile sensitive range, and different sub-bands have different sensitivities), the optimal operating frequency of the vibration unit 20 (e.g., linear motors have the highest vibration efficiency in the 50Hz-120Hz frequency band), and the low-frequency sub-bands where the open-back headphones 100 suffer the most severe sound leakage (e.g., 50Hz-120Hz, which can be dynamically adjusted according to actual hardware parameters). Its core purpose is to ensure that the filtered frequency components can be clearly perceived by the human body and efficiently converted into mechanical vibration by the vibration unit 20. "Filtering" refers to bandpass filtering in the frequency domain, which is different from the time-domain low-pass filtering of S2120. Its function is to "precisely trim" the signal in the frequency dimension, eliminating redundant frequency components to reduce the load of subsequent signal processing, while ensuring the frequency adaptability of the final vibration signal. "Target frequency band signal" is an effective signal carrier at the frequency domain level. Its core value lies in locking in the low-frequency components that need to be compensated, providing a precise frequency basis for subsequent inverse transformation back to the time domain.

[0043] S2160 is the final domain restoration stage for low-frequency signal extraction. Its core is to perform inverse fast Fourier transform (IFFT) processing on the target frequency band signal (frequency domain signal) obtained by S2150. Through the inverse operation algorithm corresponding to the fast Fourier transform, the frequency-intensity correlated signal at the frequency domain level is converted back into the time-amplitude correlated time domain signal (i.e., low-frequency signal). The "Inverse Fourier Transform Processing" is the inverse operation of the Fast Fourier Transform. Its core function is to achieve the inverse mapping between the frequency domain signal and the time domain signal, ensuring that the converted time domain signal can completely retain the frequency composition characteristics of the target frequency band signal. The "Low-Frequency Signal" is a core signal that combines frequency accuracy and time domain readability. It is different from the low-frequency time domain signal obtained in S2130. The low-frequency time domain signal focuses on reflecting the rhythm and intensity changes of the original low-frequency audio (time dimension characteristics), while the low-frequency signal focuses on reflecting the dynamic performance of the selected target frequency components in the time domain (time-domain presentation of frequency dimension characteristics). Its core role is to provide frequency dimension parameter support for the S220 step, complementing the low-frequency time domain signal, ensuring that the subsequently generated low-frequency vibration signal can match the rhythm and intensity of the original audio and accurately restore the frequency characteristics of the target frequency band. At the same time, since this step occurs synchronously with S2110-S2130, it can ensure the timing consistency of the two signals and avoid the problem of vibration and audio being out of sync.

[0044] Further, please refer to Figure 5 Step 210 also includes: S2170: Determine the first gain signal corresponding to each frequency in the low-frequency signal based on the low-frequency signal; S2180: Generates a low-frequency vibration signal based on the low-frequency time domain signal, the low-frequency frequency signal, and the first gain signal.

[0045] Step 2170 is the frequency dimension gain calibration stage for low-frequency vibration signal generation. The core is based on the low-frequency signal obtained in S2160. Through the gain calculation module in the processor of the open-back earphone 100, a corresponding gain coefficient is matched for each frequency component in the signal, ultimately forming a first gain signal corresponding to each frequency. The "first gain signal" refers to the intensity adjustment parameters (such as voltage gain coefficient, power gain coefficient, etc.) set individually for different frequency components in the low-frequency signal. Thus, different frequency components correspond to different gain values. The core basis for determining the first gain signal includes three key factors: first, the sensitivity characteristics of human tactile perception, such as assigning a higher gain to the core tactile frequency band of 50Hz-120Hz and appropriate gains to the edge frequency bands of 20Hz-50Hz and 120Hz-150Hz to ensure clear vibration perception in sensitive frequency bands; second, the frequency response characteristics of the vibration unit 20, such as the frequency response characteristics of the vibration unit 20. The first step involves optimizing the gain of high-efficiency frequency bands and appropriately increasing the gain of low-efficiency frequency bands to avoid attenuation of vibration effects at certain frequencies due to hardware characteristics. The second step involves addressing the sound leakage loss pattern of open-back headphones by increasing the gain weight of the low-frequency sub-bands that suffer the most severe sound pressure loss due to sound leakage, thus achieving targeted compensation. The core function of this step is to optimize the vibration intensity adaptability of each frequency component through frequency-specific gain adjustment, avoiding the weak or excessively strong tactile perception of some low-frequency components due to uneven intensity of each frequency in the original signal or differences in hardware characteristics, and providing balanced and adaptable gain support for subsequent signal fusion.

[0046] Step S2180 is the multi-parameter fusion and final signal synthesis stage of low-frequency compensation. The core is to integrate the rhythm and intensity characteristics of the low-frequency time domain signal, the target frequency band characteristics of the low-frequency frequency signal, and the frequency-specific intensity calibration characteristics of the first gain signal. The signal fusion algorithm in the processor completes the integration and processing of multi-dimensional parameters, and finally generates a low-frequency vibration signal with synchronization, accuracy and adaptability. Specifically, the fusion process is based on a low-frequency time-domain signal framework—preserving its amplitude variation trend reflecting the original low-frequency audio rhythm (such as the peak of drum impact and the decay process of notes) to ensure real-time synchronization between the vibration signal and the audio rhythm; using the low-frequency frequency signal as a frequency constraint—limiting the frequency components of the vibration signal to only the selected target frequency band (such as 50Hz-120Hz) to avoid interference from redundant frequency components; using the first gain signal as the basis for intensity adjustment—applying corresponding gain coefficients to each frequency component in the low-frequency signal to achieve differentiated optimization of vibration intensity for different frequency components; after the fusion of the three, waveform optimization (such as converting the signal into an adaptive sine wave or pulse wave) and dynamic range calibration can be performed according to the hardware parameters of the vibration unit 20 (such as rated voltage and maximum vibration amplitude) to ensure that the signal can accurately restore the rhythm and frequency characteristics of the original low frequency and can be efficiently converted into comfortable and clear mechanical vibration by the vibration unit 20. The resulting low-frequency vibration signal achieves triple optimization of "rhythm synchronization - frequency accuracy - intensity adaptation", providing core guarantee for subsequent vibration transmission and low-frequency tactile compensation effects.

[0047] In one embodiment of the present invention, please refer to Figure 6 Step 30 and beyond also includes: S40: Determine the ambient noise intensity corresponding to the ambient noise signal based on the ambient noise signal; S41: Determine the second gain signal based on the ambient noise intensity; S42: Obtain the environmental modulation signal based on the low-frequency vibration signal and the second gain signal; S43: Inputs the ambient modulation signal to the vibration unit 20 of the open-back headphone 100.

[0048] In step S40, the ambient noise signal under the wearing scenario is collected through the microphone (or pickup module) built into the open-back headphones 100. This includes full-frequency noise components such as traffic noise, human voice, and indoor background noise. After real-time preprocessing, such as removing extreme frequency bands beyond the range of human hearing through bandpass filtering and eliminating crosstalk of the headphones' own audio signal through adaptive filtering, the objective intensity value of the ambient noise is determined using an acoustic intensity quantization algorithm. The "ambient noise signal" is the original electrical signal that directly reflects the acoustic environment of the wearing scenario. The sampling rate is consistent with the audio signal (e.g., 44.1kHz) to ensure timing synchronization. The "ambient noise intensity" is a quantitative representation of the noise signal energy. A-weighting is used because it closely matches the human ear's perception characteristics of noise at different frequencies, accurately reflecting the degree of interference of ambient noise on the user's low-frequency vibration perception. The core function of this step is to provide an objective environmental judgment basis for subsequent dynamic adjustment of vibration intensity, avoiding vibration perception failure or over-sensing due to ambient noise interference.

[0049] Step S41 is the environmental adaptation gain calibration stage for low-frequency vibration compensation. The core is to match and calculate the gain coefficient corresponding to the current noise intensity based on the environmental noise intensity value obtained in S40, and finally generate a second gain signal that dynamically changes with the environment. This is achieved by using a preset "noise intensity - gain coefficient" mapping relationship (this mapping relationship is calibrated by user tactile perception test, for example: when the noise intensity is <40dB (quiet environment), the gain coefficient is 1.0; when the noise intensity is ≤40dB (normal environment), the gain coefficient increases linearly to 1.5; and when the noise intensity is ≥60dB (noisy environment), the gain coefficient increases linearly to 1.8). The "second gain signal" is a global intensity adjustment parameter that is distinct from the first gain signal (frequency-specific gain). It is a time-domain continuous sequence of gain values ​​that is completely synchronized with the frame length and sampling rate of the low-frequency vibration signal. During the determination process, the gain value is smoothed by a sliding window (window length 5ms) to avoid drastic fluctuations in the gain value due to sudden changes in noise intensity. The core function of this step is to ensure, through dynamic gain calibration, that the vibration intensity is sufficient to overcome noise interference and be perceived in noisy environments, and that the vibration intensity is moderate in quiet environments to avoid discomfort, thus achieving precise adaptation of vibration intensity to the environment.

[0050] Step S42 performs time-domain weighted fusion processing on the second gain signal generated in S41 and the original low-frequency vibration signal. Specifically, this is achieved through frame-by-frame multiplication: first, the amplitude range of the second gain signal is normalized to match the low-frequency vibration signal (e.g., 0-3.3V, matching the rated voltage of vibration unit 20); then, the amplitude of each frame of low-frequency vibration signal is multiplied by the corresponding frame's second gain value, while preserving the original frequency composition and rhythmic characteristics of the low-frequency vibration signal (e.g., the time-domain envelope of drumbeats, frequency distribution of the target frequency band). Only the overall intensity of the signal is dynamically adjusted, ultimately generating an environmental modulation signal adapted to the current ambient noise. The "environmental modulation signal" is a vibration-driven signal that incorporates environmental adaptation features. Its core characteristics are that it inherits the audio matching (precise rhythm and frequency) of the original low-frequency vibration signal and possesses environmental adaptability (dynamic adjustment of intensity with noise). The core function of this step is to ensure the effectiveness and comfort of vibration perception in different environments through intensity modulation without changing the core audio characteristics of the vibration signal.

[0051] Step S43 is the final execution stage of environmental adaptation for low-frequency vibration compensation. Its core is to transmit the environmental modulation signal generated in S42 to the vibration unit 20 in contact with the ear without attenuation through the headphone's internal drive circuit (such as a power amplifier circuit and impedance matching circuit), ensuring that the signal parameters (voltage, waveform, frequency) are fully adapted to the hardware characteristics of the vibration unit 20. After receiving the signal, the vibration unit 20 converts the electrical signal into mechanical vibration that matches the intensity of the environmental modulation signal. Specifically, in quiet environments, it vibrates at a basic intensity to avoid excessive vibration causing ear discomfort; in noisy environments, it vibrates at an enhanced intensity to overcome environmental noise interference, ensuring that the user can clearly perceive the tactile vibration synchronized with the low-frequency audio. This step, through the execution of the environmental modulation signal, achieves a dual low-frequency compensation effect of "audio feature matching + environmental intensity adaptation." It can stably guarantee the low-frequency tactile compensation experience of the open-back headphones 100 in different acoustic environments without manual intervention, bypassing the interference of environmental noise on low-frequency perception and further improving the all-scenario adaptability of the compensation solution.

[0052] In one embodiment, when a user wears an open-back headset 100 that applies this low-frequency compensation method while riding the subway, the built-in microphone of the headset can continuously collect ambient noise signals under human control. When the subway accelerates and produces a loud roar or when the station announcement is played, the processor calculates in real time that the ambient noise intensity suddenly increases from 70 dB during stable operation to 85 dB. According to the preset noise-gain mapping relationship, the system immediately increases the second gain signal from 1.0 to 1.6. Subsequently, the original low-frequency vibration signal is fused with the enhanced second gain signal to generate an ambient modulation signal with significantly increased intensity. Finally, the enhanced signal is input to the vibration unit 20, so that even though the ambient noise almost completely masks the music, the user can still clearly feel the enhanced low-frequency vibration rhythm through the auricle. When the subway resumes stable operation or the announcement ends and the ambient noise intensity drops back to 75 dB, the system automatically decreases the second gain signal to 1.2, restoring the vibration intensity to a comfortable level that matches the current environment, thereby maintaining the best low-frequency tactile compensation effect throughout the entire subway journey.

[0053] In one embodiment of the present invention, please refer to Figure 7 Step 30 and beyond also includes: S50: Receives vibration drive commands from the outside; S51: Generates a vibration drive signal according to the vibration drive command; S52: Input the vibration drive signal to the vibration unit 20 of the open-back headphone 100.

[0054] In step S50, the processor of the open-back headphones 100 receives a vibration drive command from an external source. This "vibration drive command" does not originate from the audio signal playing inside the headphones, but rather from an external device or system, such as a command received via Bluetooth from a mobile game application, operating system, or instant messaging software on a smartphone. This command itself is a digital data packet containing control information, explicitly instructing the headphones to perform a specific vibration task unrelated to the current audio content.

[0055] In step S51, the processor generates a vibration drive signal according to the vibration drive instruction. In this step, the processor parses the received instruction data packet and extracts the defined vibration parameters, such as the vibration waveform (e.g., sine wave, square wave), duration, intensity (amplitude), and complex rhythmic patterns (e.g., a "short-short-long" pulse sequence). Subsequently, the module synthesizes a corresponding vibration drive signal that can directly drive the vibration unit 20 based on these parameters. This signal is a standard electrical signal, but its content and timing are entirely determined by external instructions and are independent of the internal audio processing pipeline.

[0056] In step S52, the processor inputs a vibration drive signal to the vibration unit 20 of the open-back headphones 100. The generated vibration drive signal is directly transmitted to the driver circuit of the vibration unit 20, driving it to produce physical vibrations that are completely consistent with the external command requirements. Thus, the vibration unit 20, as an actuator, completes the full conversion from external digital commands to the user's tactile sensation.

[0057] Specifically, when a user wears the open-back headphones 100 to play a mobile game, when the player character is attacked or obtains a special item, the mobile game application sends a specific vibration drive command to the headphones via Bluetooth. Upon receiving the command, the signal processing module at the headphone end immediately analyzes the parameters it contains (such as vibration mode, intensity, and duration) and generates an independent vibration drive signal that is unrelated to the currently playing audio. This signal may be a set of designed short pulse sequences to simulate the feeling of impact, or a continuous strong vibration to simulate the effect of obtaining an energy item. Finally, the vibration drive signal is directly transmitted to the vibration unit 20 of the open-back headphones 100, allowing the player to feel tactile feedback with specific meaning synchronized with game events through their ears while hearing game sound effects, thereby greatly enhancing the immersion and interactive experience of the game.

[0058] In one embodiment, please refer to Figure 8 Step 30 and beyond also includes: S60: Obtain user operation commands; S61: Generates an operation confirmation vibration signal based on the user's operation instructions; S62: Input the operation confirmation vibration signal to the vibration unit 20 of the open-back headphone 100.

[0059] In step S60, the system acquires user operation commands through the interactive module integrated in the open-back headset 100, such as a touch panel, physical buttons, or a voice recognition unit. When the user performs a specific operation, such as clicking or double-clicking the headset panel to answer a call, switch songs, wake up the voice assistant, or adjust the volume, the interactive module detects this operation intention, converts it into a clear digital control command, i.e., a user operation command, and transmits it to the signal processing system.

[0060] In step S61, the system generates an operation confirmation vibration signal based on the user's operation command. Upon receiving the command, the signal processing module does not generate vibration from the audio signal, but instead invokes a preset specific vibration waveform pattern that is unrelated to the current audio content. For example, it may generate a brief, moderately intense single pulse, or a unique "tick" rhythm sequence, as the operation confirmation vibration signal.

[0061] In step S62, the system inputs an operation confirmation vibration signal to the vibration unit 20 of the open-back headphones 100. The vibration unit 20 then generates a corresponding physical vibration based on this signal. The user perceives this brief but clear vibration through the skin of their ear, thus confirming intuitively and without obstruction that their operation has been successfully recognized and executed by the system without having to check the indicator lights on their phone or headphones.

[0062] Specifically, a runner is wearing the open-back headphones 100 of this invention, listening to music while running in a park. When he wants to switch to the next song, he doesn't need to take out his phone; instead, he simply touches the touch panel on the headphones' shell. The touch panel detects this specific tap gesture, recognizes it as a "next song" command, and transmits it to the processor. The processor then obtains the corresponding user operation instruction based on the tap gesture. Subsequently, the processor generates an operation confirmation vibration signal based on the user operation instruction. This signal is designed as a short and crisp pulse waveform to distinguish it from the low-frequency compensation vibration of the music. Finally, the system inputs the operation confirmation vibration signal to the vibration unit 20 of the open-back headphones 100, and the runner's ear immediately feels a clear "tick" vibration. This tactile feedback confirms that the instruction has been successfully received and the song has been switched, allowing him to seamlessly and safely complete the operation without interrupting his running rhythm or distracting his eyes from checking his phone. This greatly improves the convenience and reliability of human-computer interaction in mobile scenarios.

[0063] In one embodiment, please refer to Figure 9 The audio signal is a dual-channel audio signal, and the vibration unit 20 includes a left ear vibration unit 20 and a right ear vibration unit 20; The step of acquiring the low-frequency band signal from the audio signal of the sound-emitting unit 10 of the input open-back headphone 100 includes: Step 11: Based on the dual-channel audio signal, obtain the low-frequency band signal of the left channel and the low-frequency band signal of the right channel; The steps for generating a low-frequency vibration signal based on a low-frequency band signal include: Step 21: Generate the original vibration signal of the left channel based on the low-frequency band signal of the left channel; Step 22: Generate the original vibration signal of the right channel based on the low-frequency band signal of the right channel; Step 23: Extract the amplitude characteristics of the original vibration signal of the left channel and the original vibration signal of the right channel at the same time; Step 24: Based on the amplitude characteristics of the original vibration signal of the right channel and the original vibration signal of the left channel, obtain the left channel allocation coefficient and the right channel allocation coefficient. Step 25: Generate the first low-frequency vibration signal based on the original vibration signal of the left channel and the left channel allocation coefficient; Step 26: Generate a second low-frequency vibration signal based on the original vibration signal of the right channel and the right channel allocation coefficient; The step of inputting a low-frequency vibration signal to the vibration unit 20 of the open-back headphone 100 includes: Step 31: Input the first low-frequency vibration signal to the left ear vibration unit 20; Step 32: Input the second low-frequency vibration signal into the right ear vibration unit 20.

[0064] In step 11, the processor filters the full-frequency signals of the left and right channels separately using a preset low-pass filter. This step aims to separate and extract components within a specific frequency range (e.g., 20Hz–150Hz) from the complex audio waveform of each channel, thereby independently obtaining the low-frequency band signals of the left and right channels, i.e., sub-signals containing only the low-frequency components of the left and right channels, respectively. The two-channel audio signal refers to an electrical signal containing independent audio data from the left (L) channel and the right (R) channel. During recording and mixing, the two channel signals typically carry different audio details (such as instrument placement and vocal localization) and phase differences, collectively creating a stereo listening experience for the user.

[0065] In steps 21 and 22, the processor processes the low-frequency band signals of the left and right channels in parallel. Through a series of signal processing techniques (such as full-wave rectification and low-pass filtering), the envelope of the signal intensity is calculated, thereby generating the original vibration signals of the left and right channels. Specifically, these two signals are voltage profiles that vary with time, respectively preserving the temporal intensity information such as rhythm and impact force corresponding to the two low-frequency signals.

[0066] In step 23, the processor performs a collaborative analysis on the two original vibration signals from the left and right sides. Within a strictly synchronized, extremely short time window (e.g., every 10 milliseconds), it calculates and extracts amplitude features that represent the signal strength in real time. The amplitude features can be the root mean square value (RMS, reflecting quantitative indicators such as average power or peak value) of the signal within the time window. Understandably, this step aims to capture the energy strength comparison of the two-channel signals at the same moment in real time.

[0067] In step 24, the processor calculates the left and right channel allocation coefficients based on the two amplitude features extracted in step 23 using a preset weighting mapping function or decision algorithm. These two coefficients are typically values ​​between 0 and 1, and the core calculation logic is: the stronger amplitude feature will receive a coefficient close to 1, while the weaker one will receive a coefficient close to 0. For example, a normalized ratio can be used for calculation: Left channel allocation coefficient = Left amplitude feature / (Left amplitude feature + Right amplitude feature).

[0068] In steps 25 and 26, the system performs modulation calculations, fusing the original vibration signals (carrying rhythm and intensity) of the left and right channels with the calculated channel allocation coefficients. The result is a low-frequency vibration signal that ultimately drives a vibration unit 20.

[0069] In steps 31 and 32, the first low-frequency vibration signal generated in steps 25 and 26 is sent to the physical left ear vibration unit 20, and the second low-frequency vibration signal is sent to the right ear vibration unit 20 to drive it to generate corresponding physical vibration. Through the independent controlled operation of these two vibration units 20, an immersive tactile experience that precisely corresponds to the position of the stereo sound image is finally achieved on the user's ears.

[0070] In one embodiment, a gamer is wearing an open-back headset 100 of the present invention to play a first-person shooter game, and the game audio engine renders a two-channel audio signal containing rich spatial information in real time.

[0071] When an explosion occurs not far to the left of the controlled game character, the processor immediately separates the low-frequency signal of the left channel (containing the low-frequency boom of the explosion) and the low-frequency signal of the right channel (mainly containing ambient background noise) from the game audio stream. Based on the low-frequency signals of the left and right channels, the system generates the original vibration signal of the left channel (showing the violent amplitude change of the explosion impact) and the relatively smooth original vibration signal of the right channel, respectively.

[0072] Subsequently, at the moment of the explosion, the system extracted that the amplitude feature of the left channel was significantly greater than that of the right channel. The system calculated the allocation coefficient of the left channel to be close to 1.0 and the allocation coefficient of the right channel to be close to 0.0 using a preset algorithm. The system multiplied the strong signal of the left channel with the high allocation coefficient to generate a strong first low-frequency vibration signal, and multiplied the weak signal of the right channel with the low allocation coefficient to obtain a second low-frequency vibration signal that was almost zero.

[0073] Finally, the vibration feedback only applies to the player's left ear vibrating unit 20, while the right ear remains essentially still. This precise tactile feedback allows players to intuitively perceive the location of the explosion not only through hearing but also through touch, greatly enhancing the game's immersion and situational awareness. When the game character turns to the right and encounters enemy fire, the above processing flow is instantly reversed, and the vibration is precisely switched to the right ear, achieving a dynamic spatial tactile experience that is completely synchronized with vision and hearing.

[0074] This invention also proposes an open-back headphone 100 for implementing any of the headphone low-frequency compensation methods described above. Please refer to [link to relevant documentation]. Figure 10 The open-back headphone 100 includes a signal processing module, a vibration unit 20, and a sound-generating unit 10; The signal processing module is configured to output a low-frequency vibration signal corresponding to the audio signal to be played. Vibration unit 20 is configured to receive low-frequency vibration signals; The sound unit 10 is configured to receive the audio signal to be played.

[0075] Specifically, when a user wears the open-back headphones 100 proposed in this invention, the vibration unit 20 can contact the user's ear. When the sound-emitting unit 10 receives the audio signal to be played and plays music, the signal processing module can process and analyze the audio signal to be played in real time and convert it into a low-frequency vibration signal. After receiving the low-frequency vibration signal, the vibration unit 20 can generate corresponding vibrations. For example, when the sound-emitting unit 10 plays the Nth time content of the audio signal, the Nth time content corresponds to a set of low-frequency drum beats. At this time, the vibration unit 20 generates vibrations at that time. In this way, when the user hears this set of low-frequency drum beats, he can perceive the vibration of the vibration unit 20. Even if there is a sound leakage gap between the earbud part of the open-back headphones 100 and the ear canal, the vibration tactile sensation can be used to compensate for low-frequency hearing, ensuring the acoustic performance of the open-back headphones 100 in low-frequency audio. Compared with the prior art, the beneficial effects of the open-back headphones 100 provided in this embodiment are the same as the beneficial effects of the headphone low-frequency compensation method provided in the above embodiments. Moreover, other technical features in the open-back headphones 100 are the same as the features disclosed in the methods of the above embodiments, and will not be described in detail here.

[0076] The present invention also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored, the computer program being configured to implement the steps of the headphone low-frequency compensation method described above when executed.

[0077] The present invention also proposes a computer program product comprising a computer program configured to, when executed, implement the steps of the headphone low-frequency compensation method described above.

[0078] In particular, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from a storage device. When the computer program is executed by a controller, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0079] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A low-frequency compensation method for headphones, applied to open-back headphones, characterized in that, The open-back headphones include a vibration unit and a sound-producing unit. The sound-producing unit is used to play audio signals, and the vibration unit is used to contact the ear. The low-frequency compensation method of the headphones includes: Based on the audio signal input to the sound unit of the open-back headphones, the low-frequency band signal in the audio signal is obtained; Based on the low-frequency band signal, a low-frequency vibration signal is generated; The low-frequency vibration signal is input to the vibration unit of the open-back headphones.

2. The method as described in claim 1, characterized in that, The step of generating a low-frequency vibration signal based on the low-frequency band signal includes: Based on the low-frequency band signal, a low-frequency time domain signal and a low-frequency frequency signal are obtained; The low-frequency vibration signal is generated based on the low-frequency time-domain signal and the low-frequency frequency signal.

3. The method as described in claim 2, characterized in that, The step of obtaining a low-frequency time-domain signal based on the low-frequency band signal includes: Based on the low-frequency band signal, full-wave rectification is performed to obtain a rectified signal; Based on a preset cutoff frequency, the rectified signal is subjected to low-pass filtering to obtain an envelope signal; The low-frequency time-domain signal is obtained based on the envelope signal.

4. The method as described in claim 2, characterized in that, The step of obtaining a low-frequency signal based on the low-frequency band signal includes: Based on the low-frequency band signal, perform Fast Fourier Transform processing to obtain the frequency domain spectrum; Based on a preset frequency band range, the frequency domain spectrum is filtered to obtain the target frequency band signal; The target frequency band signal is subjected to inverse Fourier transform processing to obtain the low frequency signal.

5. The method as described in claim 2, characterized in that, The step of generating the low-frequency vibration signal based on the low-frequency time-domain signal and the low-frequency frequency signal further includes: Based on the low-frequency signal, determine the first gain signal corresponding to each frequency in the low-frequency signal; The low-frequency vibration signal is generated based on the low-frequency time-domain signal, the low-frequency frequency signal, and the first gain signal.

6. The method according to any one of claims 1 to 5, characterized in that, After the step of inputting the low-frequency vibration signal to the vibration unit of the open-back headphone, the method further includes: Determine the environmental noise intensity corresponding to the environmental noise signal based on the environmental noise signal; The second gain signal is determined based on the ambient noise intensity. An environmental modulation signal is obtained based on the low-frequency vibration signal and the second gain signal; The environmental modulation signal is input to the vibration unit of the open-back headphones.

7. The method according to any one of claims 1 to 5, characterized in that, The method further includes: Receive vibration drive commands from the outside; A vibration drive signal is generated according to the vibration drive command; The vibration drive signal is input to the vibration unit of the open-back headphones.

8. The method according to any one of claims 1 to 5, characterized in that, The method further includes: Obtain user operation commands; Based on the user's operation instructions, an operation confirmation vibration signal is generated; The operation confirmation vibration signal is input to the vibration unit of the open-back headphones.

9. The method according to any one of claims 1 to 5, characterized in that, The audio signal is a dual-channel audio signal, and the vibration unit includes a left ear vibration unit and a right ear vibration unit. The step of obtaining the low-frequency band signal from the audio signal input to the sound unit of the open-back headphones includes: Based on the dual-channel audio signal, the low-frequency band signal of the left channel and the low-frequency band signal of the right channel are obtained; The step of generating a low-frequency vibration signal based on the low-frequency band signal includes: Based on the low-frequency band signal of the left channel, the original vibration signal of the left channel is generated; Based on the low-frequency band signal of the right channel, the original vibration signal of the right channel is generated; Extract the amplitude characteristics of the original vibration signal of the left channel and the original vibration signal of the right channel at the same time. Based on the amplitude characteristics of the original vibration signal of the right channel from the original vibration signal of the left channel, the left channel allocation coefficient and the right channel allocation coefficient are obtained. A first low-frequency vibration signal is generated based on the original vibration signal of the left channel and the allocation coefficient of the left channel; A second low-frequency vibration signal is generated based on the original vibration signal of the right channel and the allocation coefficient of the right channel; The step of inputting the low-frequency vibration signal to the vibration unit of the open-back headphone includes: The first low-frequency vibration signal is input to the left ear vibration unit; The second low-frequency vibration signal is input to the right ear vibration unit.

10. An open-back headphone for implementing the headphone low-frequency compensation method as described in any one of claims 1 to 9, characterized in that, The open-back headphones include a signal processing module, a vibration unit, and a sound-generating unit. The signal processing module is configured to output a low-frequency vibration signal corresponding to the audio signal to be played. The vibration unit is configured to receive the low-frequency vibration signal; The sound unit is configured to receive the audio signal to be played.

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