Noise adjusting method of sonometer and noise generator thereof

Abstract

The invention particularly relates to a noise adjustment method of an audiometer and a noise generator thereof, and the method comprises the following steps: constructing a noise database, the types of the noise comprising analog noise, random noise and mixed noise; the frequency range and amplitude data during pure tone output are obtained, a preselection scheme of masking noise matched with the pure tone is generated from the corresponding type according to the input instruction, and the preselection scheme comprises the duration time, the expected frequency range and the expected amplitude of the selected masking noise; superposing and outputting the selected masking noise and the pure tone, obtaining the mixed tone segment signal again at the vibrating diaphragm, and performing time-frequency conversion to generate a waveform frequency spectrum; based on the waveform frequency spectrum, removing the waveform frequency spectrum calculated according to the frequency range and the amplitude data of the pure tone, then calculating to obtain the actual frequency range and the actual amplitude of the masking noise, and adjusting the frequency range and the amplitude output by the masking noise according to the actual frequency range and the actual amplitude. Therefore, the actual frequency range and the actual amplitude are infinitely close to the expected frequency range and the expected amplitude respectively.

Description

Technical Field

[0001] The present invention relates to the technical field of sound-generating device control, and in particular to a noise adjustment method of an audiometer and a noise generator thereof. Background Art

[0002] An audiometer is an electronic instrument that tests hearing function and is widely used in the inspection and diagnosis of hearing impairment. The noise generator is a device that can generate random or predetermined sound waves. Usually, in hearing tests, the noise generator is used to simulate environmental noise or as a masking noise to evaluate the hearing level of the subject in different noise environments. In the application scenarios of existing sound-generating devices such as audiometers, the quality of sound output is affected due to the differences in circuit settings or other hardware devices, as well as the interference of internal or external noise. What the audiometer needs during the test is a stable noise output to judge the user's hearing by mixing pure tones. Traditional noise generators are only responsible for generating noise signals and then outputting them and superimposing them with pure tones, and further use filtering circuits to filter out redundant noise of specific frequencies. However, these conventional methods have certain limitations and cannot solve the problem of redundant noise generated inside the device. Moreover, the noise signal is relatively complex. After transmission loss, the local noise signal is lost, or when used as environmental noise, it is easy to overlap with the pure tones, or even cover the output signal of the pure tones, and cannot provide the subject with a stable and consistent superimposed sound, which ultimately affects the accuracy of the test results. Summary of the invention

[0003] In order to solve the problems existing in the above-mentioned prior art, one of the purposes of the present invention is to provide a noise adjustment method for an audiometer, which can adjust and accurately form the corresponding masking noise in real time, effectively avoid the influence of redundant noise caused by internal equipment, etc., and cooperate with the pure tone superposition output to make the test results of the subjects more accurate. The second purpose of the present invention is to provide a noise generator for an audiometer, which cooperates with the application of the above-mentioned method to adjust the frequency range and amplitude of the masking noise in real time to better adapt to the formation of the masking noise of each pure tone superposition.

[0004] The noise adjustment method of an audiometer according to the present invention comprises the following steps:

[0005] S1. Construct a noise database, where the types of noise include simulated noise, random noise and mixed noise;

[0006] S2, obtaining the frequency range and amplitude data of the pure tone output, and generating a pre-selected scheme of masking noise adapted to the pure tone from the corresponding type according to the input instruction, wherein the pre-selected scheme includes the duration, expected frequency range and expected amplitude of the selected masking noise;

[0007] S3. Superimpose the selected masking noise and the pure tone and output the result, and then obtain the mixed tone segment signal again at the diaphragm, and generate a waveform spectrum through time-frequency conversion;

[0008] S4. Based on this waveform spectrum, remove the waveform spectrum calculated according to the frequency range and amplitude data of the pure tone, and then calculate the actual frequency range and actual amplitude of the masking noise, and adjust the frequency range and amplitude of the output of the masking noise accordingly, so that the actual frequency range and actual amplitude are infinitely close to the desired frequency range and desired amplitude respectively.

[0009] In one embodiment, in the step S4, the specific method for adjusting the frequency range and amplitude of the output of the masking noise is: divide 20 Hz to 20 kHz into several frequency bands according to the corresponding octaves, and use the PID algorithm to adjust the signal generation of the masking noise. The PID parameter combinations are independently set for each frequency band, and the PID parameter combination library is stored and recorded.

[0010] In one embodiment, the method further includes: constructing an LSTM neural network to record the control effect data in real time. When the reduction rate is less than 10% in consecutive multiple control cycles, generate a virtual signal for parameter space exploration, and update the PID parameter combination library through reinforcement learning.

[0011] In one embodiment, the simulated noise is a noise set collected from the outside world and simulated to be formed under different environments.

[0012] In one embodiment, the random noise includes pink noise, speech noise, broadband white noise, and narrowband white noise.

[0013] In one embodiment, the mixed noise is an overlapping noise randomly mixed by selecting two or more of the simulated noise and the random noise.

[0014] In one embodiment, in the step S2, calculate the waveform spectra of the pure tone and the masking noise according to the frequency range and amplitude data. When the overlap rate of the two waveform spectra is higher than 25%, give a prompt and suggest resetting the input command.

[0015] In one embodiment, before the masking noise and the pure tone are combined and output, according to the input command, the masking noise is filtered by a filter to remove unnecessary frequency components.

[0016] A noise generator of an audiometer according to the present invention applies the above-mentioned noise adjustment method for an audiometer. The noise generator includes:

[0017] A control unit, configured to separately obtain data of the pure tone, data of the masking noise, and data after the superposition output of the pure tone and the masking noise, and perform feedback adjustment after PID calculation;

[0018] A signal source, connected to the control unit, and configured to adjust the generated noise signal based on an input instruction and the feedback of the control unit;

[0019] A frequency control module, respectively connected to the control unit and the signal source, and configured to adjust the frequency range of the noise signal by changing the settings of a filter;

[0020] An amplitude control module, respectively connected to the control unit and the signal source, and configured to adjust the intensity or amplitude of the noise signal;

[0021] A filter, connected to the signal source, and configured to filter out unnecessary frequency components according to an input instruction.

[0022] In one embodiment, the noise generator includes an analog noise generator and a digital noise generator.

[0023] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0024] The present invention provides a method for adjusting noise of an audiometer. Through modeling and learning, a corresponding masking noise is adapted with a noise database, combined with the output of a pure tone, and the sound after output is collected again to adjust the frequency range and amplitude of the masking noise in real time, so as to ensure that when the audiometer judges the hearing condition of a subject, the output of the masking noise is stable and does not affect the output of the pure tone due to the existence of redundant noise, thereby providing a reliable test result, which is of great significance for accurately evaluating the hearing health condition of the subject and for timely detecting and diagnosing hearing diseases.

[0025] The present invention also provides a noise generator of an audiometer. The device applies the above method to perform real-time dynamic adjustment on the frequency range and amplitude of the masking noise to better adapt to the formation of the masking noise superimposed with each pure tone. At the same time, the noise generator combines the use of PID technology to adjust parameters, respectively corresponding to adjusting the noise sets under different instructions such as pink noise, speech noise, broadband white noise, and narrowband white noise, and constructs an LSTM neural network to strengthen learning and update the PID parameter combination library. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is an overall flowchart of a method for adjusting noise of an audiometer according to the present invention;

[0027] Figure 2 is a connection schematic diagram of a noise generator of an audiometer according to the present invention. DETAILED DESCRIPTION

[0028] The drawings are only used for illustrative purposes and should not be construed as limitations on this patent. In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be said that the internal connection of two components is connected. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The technical solution of the present invention is further explained below in conjunction with the accompanying drawings and embodiments.

[0030] like Figure 1 As shown, a noise adjustment method for an audiometer of the present invention comprises the following steps:

[0031] S1. Build a noise database. The types of noise include simulated noise, random noise and mixed noise.

[0032] S2, obtaining the frequency range and amplitude data of the pure tone output, and generating a pre-selected scheme of masking noise adapted to the pure tone from the corresponding type according to the input instruction, the pre-selected scheme including the duration, expected frequency range and expected amplitude of the selected masking noise;

[0033] S3, superimposing the selected masking noise with the pure tone and outputting the mixed tone signal again at the diaphragm, and generating a waveform spectrum through time-frequency conversion;

[0034] S4. Based on the waveform spectrum, the waveform spectrum calculated according to the frequency range and amplitude data of the pure tone is removed, and then the actual frequency range and actual amplitude of the masking noise are calculated, and the frequency range and amplitude of the masking noise output are adjusted accordingly, so that the actual frequency range and actual amplitude are infinitely close to the expected frequency range and expected amplitude respectively.

[0035] The present invention provides a method for adjusting the noise of an audiometer. Through modeling and learning, a corresponding masking noise is adapted from a noise database, which is combined with the pure tone output, and the output sound is collected again to adjust the frequency range and amplitude of the masking noise in real time. It is mainly based on the waveform diagram obtained secondly at the diaphragm. After removing the pure tone part from the waveform diagram, it is analyzed whether the masking noise is accurate, whether there is redundant noise, and whether the actual frequency range and actual amplitude reach the expected frequency range and expected amplitude respectively, so as to ensure that when the audiometer judges the hearing condition of the subject, the masking noise output is stable and will not affect the output of the pure tone due to the existence of redundant noise, thereby providing reliable test results. This is of great significance for accurately evaluating the hearing health condition of the subject and for timely detecting and diagnosing hearing diseases.

[0036] Further, in step S4, the specific method for adjusting the frequency range and amplitude of the masking noise output is as follows: The range from 20 Hz to 20 kHz is divided into several frequency bands according to the corresponding octave. The PID algorithm is used to adjust the signal generation of the masking noise. The PID parameter combinations are independently set for each frequency band and stored to form a PID parameter combination library. PID control is a feedback control technology widely used in industrial control systems. The PID algorithm specifically calculates the error between the set value and the current value, and adjusts the control input according to this error to achieve the stable and precise control of the system. It mainly optimizes the performance of the controller by adjusting the proportional gain Kp, integral gain Ki, and derivative gain Kd to achieve purposes such as fast response, reduction of steady-state error, and improvement of system stability. And the octave is the space occupied by the spectrum when the frequency increases by a factor of two. Since the starting frequency is random, the spectrum spaces occupied by the octaves for different starting frequency points are different. In this step, for different masking noises, their corresponding octaves are also different. For example, speech noise and broadband white noise use 1 / 3 octave, while narrowband white noise uses 5 / 12 octave. According to the corresponding octave, this section of masking noise can be divided into multiple frequency bands, and each frequency band is calculated according to the independently set PID parameters, thus forming multiple PID parameter combinations. In this way, the independent PID parameters of each frequency band are adjusted to make the entire masking noise more natural and accurately achieve dynamic adjustment. For the adjustment of the frequency range and amplitude of the masking noise, there are differences in actual applications. The adjustment of the frequency range will first determine the upper and lower limit frequencies of the masking noise, and then mainly cooperate with filters to achieve it. After adjustment, the unnecessary frequency components will be filtered to keep it within a certain range. For the dynamic adjustment of the amplitude of the masking noise, the adjustment signal is output according to the following PID algorithm formula:

[0037] u(0) = 0;

[0038] Δu(k) = K p ·[e(k) - e(k - 1)] + Ki ·e(k) + K d ·[e(k) - 2e(k - 1) + e(k - 2)];

[0039] u(k) = u(k - 1) + Δu(k),

[0040] e(k) represents the input deviation between the given value and the measured value, k represents the k-th sampling period, and the adjustment signal u(k) is calculated and output to achieve dynamic adjustment.

[0041] In addition, this method further includes step S5: constructing an LSTM neural network to record the control effect data in real time. When the reduction rate is less than 10% within, for example, 5 consecutive control periods, a virtual signal is generated to explore the parameter space, and the PID parameter combination library is updated through reinforcement learning. This step introduces an embedded online learning system, which mainly controls the flow and update of information through three gating logic units: the forget gate, the input gate, and the output gate. Through its unique structure, LSTM can effectively process the long-term dependencies in sequence data, thus realizing the autonomous evolution of control parameters.

[0042] Specifically, the simulated noise is a set of noises collected from the outside world and simulated to form under different environments, such as the sound of rain, the hustle and bustle of the city, or the roar of machines in a factory. Random noise includes pink noise, speech noise, broadband white noise, and narrowband white noise. This set mainly contains relatively more regular masking noises. For example, pink noise is a noise with equal noise energy in each octave bandwidth within a relatively wide frequency range; speech noise is obtained by specially filtering white noise, with equal energy between 250Hz and 1000Hz and a 12dB energy decrease per octave between 1000Hz and 6000Hz; white noise is a noise with equal noise energy in each equal bandwidth within a relatively wide frequency range. White noise is further divided into: broadband white noise, which is fixed in a certain frequency range after filtering white noise, and its broadband is measured at the 3dB point below the peak; narrowband white noise, which has a pure tone frequency as its center frequency after filtering white noise. The mixed noise is an overlapping noise set randomly mixed with two or more segments selected from the simulated noise and random noise to better adapt to the pure tone mixed test of the audiometer and form multiple test modes.

[0043] Furthermore, to prevent masking noise from affecting the output of the pure tone during the selection and adjustment process, in step S2, the waveform spectra of the pure tone and the masking noise are calculated based on the frequency range and amplitude data. When the overlap rate of the two waveform spectra is higher than 25%, a prompt is issued to recommend resetting the input instruction. This can effectively prevent the pure tone from becoming blurred and affecting the actual test results after the pure tone and the masking noise selected and adjusted by the noise database are superimposed and output. When the coverage rate is higher than 25% during the superposition, a prompt is added to the input instruction to determine that this test will partially cover the pure tone. Unless this setting is specifically set for the subject, different required instructions should be re-entered, such as changing the noise type or manually adjusting the required frequency range and amplitude, to ensure that the output of the pure tone is not affected by the co-frequency coverage of the masking noise. Moreover, before the masking noise and the pure tone are combined and output, according to the input instruction, the masking noise will be filtered by a filter to remove unnecessary frequency components. This is mainly to further prevent the adjustment of the frequency range from easily exceeding the required range of the original masking noise, and the redundant noise generated inside the device may also form these unnecessary frequency components.

[0044] As Figure 2 shown, a noise generator of an audiometer according to the present invention applies the above-mentioned noise adjustment method for an audiometer. The noise generator includes:

[0045] A control unit, configured to respectively obtain data of the pure tone, data of the masking noise, and data after the pure tone and the masking noise are superimposed and output, and perform feedback adjustment after PID calculation, mainly applying operations and setting various parameters of the noise generator, especially adjusting different parameter combinations of each frequency band divided according to the corresponding octave of different masking noises in the above PID algorithm to adapt to the real-time adjustment of the masking noise corresponding to the pure tone and its superimposed effect;

[0046] A signal source, connected to the control unit, adjusts the generated noise signal based on the input instruction and the feedback of the control unit. This is the basic part for generating the noise signal, including the above-mentioned analog noise, random noise, and mixed noise;

[0047] A frequency control module, respectively connected to the control unit and the signal source, is configured to adjust the frequency range of the noise signal by changing the settings of the filter. This module is applied in combination with the above PID algorithm. For the dynamic adjustment of the frequency range of the masking noise, the upper and lower limit frequencies need to be determined first. Without exceeding this upper and lower limit range, in cooperation with the adjustment of the filter, the output frequency range is restricted, and then the frequency of the masking noise is adjusted;

[0048] The amplitude control module is respectively connected to the control unit and the signal source and is used to adjust the intensity or amplitude of the noise signal. This module also applies the above PID algorithm. The real-time dynamic adjustment of the intensity or amplitude of the masking noise is mainly the change of the parameter combination in the formula. According to different masking noises, several frequency bands are divided according to the corresponding octave, and the PID parameters are independently set for different frequency bands to form this parameter combination;

[0049] The filter is connected to the signal source and is used to filter out unnecessary frequency components according to the input instruction.

[0050] The device of the present invention applies the above method to perform real-time dynamic adjustment on the frequency range and amplitude of the masking noise so as to better adapt to the formation of the masking noise for each pure tone superposition.

[0051] Specifically, the noise generator includes an analog noise generator and a digital noise generator. The analog noise generator uses an analog circuit to generate a noise signal, and the digital noise generator uses digital signal processing technology to generate a noise signal. The combined use can more conveniently collect or form the above-mentioned analog noise, random noise, and even mixed noise, so as to form more combination possibilities for the test of the audiometer and improve the test accuracy.

[0052] In the description of the present application, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, up, down, left, right", "horizontal, vertical, horizontal", and "top, bottom" is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the protection scope of the present application.

[0053] In the figure, the description of the positional relationship is only for illustrative purposes and cannot be understood as a limitation on this patent; obviously, the above-mentioned embodiments of the present invention are only examples for clearly explaining the present invention and are not limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A noise adjustment method for an audiometer, characterized in that: The following steps are involved: S1. Construct a noise database, where the types of noise include simulated noise, random noise and mixed noise; S2, obtaining the frequency range and amplitude data of the pure tone output, and generating a pre-selected scheme of masking noise adapted to the pure tone from the corresponding type according to the input instruction, wherein the pre-selected scheme includes the duration, expected frequency range and expected amplitude of the selected masking noise; S3, superimposing the selected masking noise and the pure tone and outputting them, acquiring the mixed sound segment signal again at the diaphragm, and generating a waveform spectrum through time-frequency conversion; S4. Based on the waveform spectrum, remove the waveform spectrum calculated according to the frequency range and amplitude data of the pure tone, calculate the actual frequency range and actual amplitude of the masking noise, and adjust the frequency range and amplitude of the masking noise output accordingly, so that the actual frequency range and actual amplitude are infinitely close to the expected frequency range and expected amplitude, respectively.

2. The noise adjustment method of an audiometer according to claim 1, characterized in that: In step S4, the specific method of adjusting the frequency range and amplitude of the masking noise output is: dividing 20 Hz to 20 kHz into several frequency bands according to corresponding octaves, using a PID algorithm to adjust the signal generation of the masking noise, independently setting a PID parameter combination for each frequency band, and storing the records to form a PID parameter combination library.

3. The noise adjustment method of an audiometer according to claim 2, characterized in that: Also includes: An LSTM neural network is constructed to record control effect data in real time. When the reduction rate is less than 10% in multiple consecutive control cycles, a virtual signal is generated to explore the parameter space, and the PID parameter combination library is updated through reinforcement learning.

4. The noise adjustment method of an audiometer according to claim 1, characterized in that: The simulated noise is a set of noises collected from the outside and simulated in different environments.

5. The noise adjustment method of an audiometer according to claim 1, characterized in that: The random noise includes pink noise, speech noise, broadband white noise and narrowband white noise.

6. The noise adjustment method of an audiometer according to claim 1, characterized in that: The mixed noise is an overlapping noise obtained by randomly mixing two or more segments of the simulated noise and the random noise.

7. The noise adjustment method of an audiometer according to claim 1, characterized in that: In the step S2, the waveform spectra of the pure tone and the masking noise are calculated according to the frequency range and amplitude data, and when the overlap rate of the two waveform spectra is higher than 25%, a prompt is issued to suggest resetting the input instruction.

8. The noise adjustment method of an audiometer according to claim 5, characterized in that: Before the masking noise is combined with the pure tone and output, the masking noise is filtered through a filter to filter out unnecessary frequency components according to an input instruction.

9. A noise generator for an audiometer, characterized in that: According to the noise adjustment method of an audiometer as claimed in any one of claims 2 to 8, the noise generator comprises: A control unit, used to respectively obtain the data of the pure tone, the data of the masking noise, and the data after the pure tone and the masking noise are superimposed and output, and perform feedback adjustment after PID calculation; a signal source connected to the control unit, and adjusting the generated noise signal based on input instructions and feedback from the control unit; A frequency control module, connected to the control unit and the signal source, respectively, for adjusting the frequency range of the noise signal by changing the setting of the filter; an amplitude control module, connected to the control unit and the signal source respectively, and used to adjust the intensity or amplitude of the noise signal; The filter is connected to the signal source and is used to filter out unnecessary frequency components according to the input instruction.

10. The noise generator of an audiometer according to claim 9, characterized in that: The noise generator includes an analog noise generator and a digital noise generator.

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