Acoustical laser modulation method and system and hearing aid

Abstract

The invention provides an acoustic laser modulation method and system and a hearing aid. The acoustic laser modulation method comprises the following steps: S1, acquiring an acoustic signal; s2, performing time-frequency analysis on the sound signal; s3, extracting sound signal features according to a time-frequency analysis result; s4, modulating and generating an electric signal according to the extracted sound signal characteristics; and S5, controlling a laser to output acoustic laser according to the electric signal. The acoustic laser generated by the invention can generate vibration in the cochlea of a user, so that the auditory nerve of the user generates an auditory signal.

Description

Technical Field

[0001] The present invention relates to the field of laser sound technology, and in particular to a sound laser modulation method, system and hearing aid. Background Art

[0002] Laser thermal expansion-induced sound is the interaction between laser and matter. That is, when the laser irradiates the surface of the material, the photons interact with the molecules of the material, causing the molecules to vibrate. The laser energy is absorbed by the material and converted into heat energy, causing the local temperature of the material to rise. The material undergoes thermal expansion, and this expansion propagates outward in the form of waves, thereby generating sound waves or sound fields.

[0003] For modulation methods, existing patent literature focuses on the repetition frequency of laser pulses, such as:

[0004] The patent document "A laser-induced acoustic underwater communication modulation method and device, system, and electronic device CN114826433B" proposes to use a sequence spread spectrum transformation on the codeword to be sent; using the delay difference coding rule, the spread spectrum codeword to be sent is mapped into delay information; based on the delay information, an excitation indication signal is generated so that the laser emits a corresponding laser pulse signal according to the excitation indication signal, wherein the laser pulse signal is converted into an acoustic signal underwater, thereby realizing laser-induced acoustic underwater communication modulation.

[0005] Patent document "Air to water cross-medium laser acoustic communication method based on Manchester code CN116318436A" proposes an air to water cross-medium laser acoustic communication method based on Manchester code. The signal sending end obtains data information, converts the obtained data information into binary, then performs Manchester encoding, and then performs OOK modulation and transmits it to the laser in the form of a square wave. The laser generates a laser pulse signal.

[0006] The above modulation methods target digital information, i.e. "0" and "1" information. The digital signal modulation method used is essentially the rearrangement of "0" and "1" code words for information transmission between devices. However, this modulation method cannot be used in the hearing aid field because the human ear cannot recognize this digital information. Summary of the invention

[0007] In view of the defects in the prior art, an object of the present invention is to provide an acoustic laser modulation method, system and hearing aid.

[0008] According to the present invention, a method for acoustic laser modulation is provided, comprising:

[0009] Step S1, obtaining an acoustic signal;

[0010] Step S2, performing time-frequency analysis on the sound signal;

[0011] Step S3, extracting acoustic signal features according to the time-frequency analysis results;

[0012] Step S4, generating an electrical signal by modulating the extracted acoustic signal features;

[0013] Step S5, controlling the laser to output acoustic laser according to the electrical signal.

[0014] Furthermore, the step S1 includes: receiving an acoustic signal in real time, and amplifying the signal strength of the acoustic signal.

[0015] Furthermore, the time-frequency analysis includes: performing a time domain analysis on the acoustic signal to obtain a signal strength, and performing a frequency domain analysis on the acoustic signal to obtain a signal spectrum.

[0016] Furthermore, the extraction of acoustic signal features includes: filtering the acoustic signal according to the result of time-frequency analysis, and extracting features from the filtered acoustic signal, wherein the extracted features include the start time of the positive pulse of the acoustic signal, the time when the positive pulse reaches the maximum amplitude, the maximum amplitude, and the spectrum of the acoustic signal, wherein the maximum amplitude is a voltage value.

[0017] Furthermore, the electrical signal includes a pulse sequence, in which:

[0018] The starting time of each pulse is the starting time of the positive pulse of the acoustic signal, and the ending time is the time when the positive pulse of the acoustic signal reaches the maximum amplitude;

[0019] The amplitude of each pulse is the normalized amplitude of the positive pulse of the acoustic signal multiplied by an amplification parameter, wherein the normalized amplitude includes:

[0020] The normalized result of the maximum amplitude of the voltage value of the acoustic signal, the normalized result of the maximum amplitude on the spectrum of the acoustic signal, or the normalized result of the control voltage corresponding to the maximum output amplitude of the acoustic laser.

[0021] Furthermore, the step S5 further comprises: controlling the spot diameter of the acoustic laser according to the signal spectrum.

[0022] Furthermore, the filtering range includes 20 Hz-20000 Hz.

[0023] Furthermore, the maximum processing delay of step S1 is 1 millisecond.

[0024] According to the present invention, an acoustic laser modulation system is provided, comprising:

[0025] Module M1, obtaining sound signals;

[0026] Module M2, time-frequency analysis of acoustic signals;

[0027] Module M3, extracting acoustic signal features according to the time-frequency analysis results;

[0028] Module M4, modulating and generating an electrical signal according to the extracted acoustic signal features;

[0029] Module M5, controls the laser to output acoustic laser according to the electrical signal.

[0030] A hearing aid provided by the present invention comprises the acoustic laser modulation system, and the acoustic laser is irradiated at the ear.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention performs time-frequency analysis on the sound signal received, and modulates the result of the time-frequency analysis to generate an electrical signal for controlling the acoustic laser. The electrical signal for controlling the acoustic laser is used to control the pulse on and off of the laser, the laser pulse energy, the laser spot diameter, etc. The generated acoustic laser can generate vibrations in the human cochlea, thereby allowing the user's auditory nerve to generate auditory signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0034] Figure 1 It is the work flow chart of the present invention. DETAILED DESCRIPTION

[0035] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0036] like Figure 1 As shown, the present invention provides an acoustic laser modulation method, comprising:

[0037] Step S1, obtaining an acoustic signal.

[0038] Step S2: Perform time-frequency analysis on the sound signal.

[0039] Step S3: extracting acoustic signal features according to the time-frequency analysis results.

[0040] Step S4: Generate an electrical signal by modulating the extracted acoustic signal features.

[0041] Step S5, controlling the laser to output acoustic laser according to the electrical signal.

[0042] In step S1, the method for acquiring the acoustic signal includes receiving the acoustic signal in real time, amplifying the signal strength as required, and outputting the acoustic signal to time-frequency analysis.

[0043] In step S2, the time-frequency analysis method includes analyzing the acoustic signal in the time domain and the frequency domain, with the time domain focusing on analyzing the signal strength and the frequency domain focusing on analyzing the signal spectrum, and the maximum processing delay time of this step is 1 millisecond.

[0044] In step S3, the method for extracting the characteristics of the acoustic signal includes filtering the acoustic signal, and the filtering range can be set, and the typical value can refer to the normal human hearing range, that is, 20Hz-20000Hz. The characteristics of the filtered acoustic signal are extracted, and the characteristics include the start time of the positive pulse of the acoustic signal, the time when the positive pulse reaches the maximum amplitude, the maximum amplitude, and the spectrum of the acoustic signal, and the maximum amplitude is a voltage value.

[0045] In step S4, the electrical signal generated by modulation includes a pulse sequence. In the pulse sequence, the start time of each pulse is the start time of the positive pulse of the acoustic signal, and the end time is the time when the positive pulse of the acoustic signal reaches the maximum amplitude. In the pulse sequence, the amplitude of each pulse is the normalized amplitude of the positive pulse of the acoustic signal multiplied by an amplification parameter, and the normalized amplitude can be the normalized result of the maximum amplitude of the positive pulse of the acoustic signal, the normalized result of the peak signal amplitude on the spectrum of the acoustic signal, or the normalized result of the control voltage corresponding to the maximum output amplitude of the acoustic laser. The amplification parameter is adjusted according to the type of laser that specifically outputs the acoustic laser.

[0046] In step S5, the spot diameter of the acoustic laser can also be controlled according to the signal spectrum.

[0047] The equation for thermal expansion laser-induced acoustics is as follows:

[0048]

[0049] In the above formula, p is the sound pressure caused by laser thermal expansion, c is the sound speed, C p is the specific heat capacity of the medium, I(x,y,z,t) is the laser energy absorbed by the medium, where x, y, z are the three-dimensional coordinates of the acoustic signal receiving point, t is the time, and β is the expansion coefficient of the medium.

[0050] The above equation is a partial differential equation. One solution of this equation can be written as follows:

[0051]

[0052] In the above formula, P(ω) is the spectrum intensity of the photoacoustic signal, ω is the laser angular frequency, I0(ω) is the spectrum function of the laser pulse, A is the refractive index of the laser in the medium, P0 is the laser energy, β is the expansion coefficient of the medium, and C p is the specific heat capacity of the medium, H(ω) represents the transfer function from the laser signal to the acoustic signal, and its expression is as follows:

[0053]

[0054] In the above formula, e is a natural constant, j is an imaginary unit, r is the distance from the receiving end to the sound source, θ is the observation angle of the receiving end, ω is the laser angular frequency, μ is the laser absorption coefficient of the medium, and a is the radius of the laser spot.

[0055] According to an acoustic laser modulation system provided by the present invention, the acoustic laser modulation system can be implemented by executing the process steps of the acoustic laser modulation method, that is, those skilled in the art can understand the acoustic laser modulation method as a preferred embodiment of the acoustic laser modulation system. The system includes:

[0056] Module M1, obtaining sound signals.

[0057] Module M2: Perform time-frequency analysis on the sound signal.

[0058] Module M3: extracting acoustic signal features based on the time-frequency analysis results.

[0059] Module M4, modulates and generates an electrical signal according to the extracted acoustic signal features.

[0060] Module M5 controls the laser to output acoustic laser according to the electrical signal.

[0061] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, it is entirely possible to realize the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0062] The present invention also provides a hearing aid, which uses the above-mentioned acoustic laser modulation system to irradiate the acoustic laser at the ear position, generate vibrations in the human cochlea, and then make the user's auditory nerve generate auditory signals.

[0063] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for acoustic laser modulation, characterized in that: include: Step S1, obtaining an acoustic signal; Step S2, performing time-frequency analysis on the sound signal; Step S3, extracting acoustic signal features according to the time-frequency analysis results; Step S4, generating an electrical signal by modulating the extracted acoustic signal features; Step S5, controlling the laser to output acoustic laser according to the electrical signal.

2. The acoustic laser modulation method according to claim 1, characterized in that: The step S1 includes: receiving an acoustic signal in real time and amplifying the signal strength of the acoustic signal.

3. The acoustic laser modulation method according to claim 1, characterized in that: The time-frequency analysis includes: performing a time-domain analysis on the acoustic signal to obtain a signal strength, and performing a frequency-domain analysis on the acoustic signal to obtain a signal spectrum.

4. The acoustic laser modulation method according to claim 1, characterized in that: The method of extracting the characteristics of the acoustic signal includes: filtering the acoustic signal according to the result of the time-frequency analysis, and extracting characteristics of the filtered acoustic signal, wherein the extracted characteristics include the start time of the positive pulse of the acoustic signal, the time when the positive pulse reaches the maximum amplitude, the maximum amplitude, and the spectrum of the acoustic signal, wherein the maximum amplitude is a voltage value.

5. The acoustic laser modulation method according to claim 1, characterized in that: The electrical signal includes a pulse sequence, in which: The starting time of each pulse is the starting time of the positive pulse of the acoustic signal, and the ending time is the time when the positive pulse of the acoustic signal reaches the maximum amplitude; The amplitude of each pulse is the normalized amplitude of the positive pulse of the acoustic signal multiplied by an amplification parameter, wherein the normalized amplitude includes: The normalized result of the maximum amplitude of the voltage value of the acoustic signal, the normalized result of the maximum amplitude on the spectrum of the acoustic signal, or the normalized result of the control voltage corresponding to the maximum output amplitude of the acoustic laser.

6. The acoustic laser modulation method according to claim 3, characterized in that: The step S5 further includes: controlling the spot diameter of the acoustic laser according to the signal spectrum.

7. The acoustic laser modulation method according to claim 4, characterized in that: The filtering range includes 20Hz-20000Hz.

8. The acoustic laser modulation method according to claim 1, characterized in that: The maximum processing delay of step S1 is 1 millisecond.

9. An acoustic laser modulation system, characterized in that: include: Module M1, obtaining sound signals; Module M2, time-frequency analysis of acoustic signals; Module M3, extracting acoustic signal features according to the time-frequency analysis results; Module M4, modulating and generating an electrical signal according to the extracted acoustic signal features; Module M5, controls the laser to output acoustic laser according to the electrical signal.

10. A hearing aid, comprising the acoustic laser modulation system according to claim 9, wherein the acoustic laser is irradiated at the ear.

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