Method for detecting personal sound attenuation value of hearing protector

Abstract

The invention relates to a method for detecting a personal sound attenuation value of a hearing protector, which comprises the following steps of: respectively arranging a microphone inside and outside a left ear canal, a left ear canal and a right ear canal and outside the right ear, making a test sound when the two ears do not wear the hearing protector, obtaining respective transfer functions of the left ear and the right ear according to frequency spectrum sound pressure levels of original waveforms respectively collected by the four microphones, and calculating the personal sound attenuation value of the hearing protector according to the transfer functions of the left ear and the right ear. And the influence on the ear canal caused by the frequency response difference of the microphone and the position difference of the microphone during measurement can be eliminated. The method comprises the following steps: when both ears wear a hearing protector, making a test sound, obtaining a frequency spectrum sound pressure level which is not blocked by the hearing protector through a collection result of a microphone outside an auditory meatus, obtaining a frequency spectrum sound pressure level which is blocked by the hearing protector through a collection result of a microphone in the auditory meatus, and obtaining sound attenuation generated by wearing the hearing protector by making a difference between the two frequency spectrum sound pressure levels. And obtaining a personal sound attenuation value. The sound attenuation is compensated through the transfer function, so that the obtained personal sound attenuation value is small in uncertainty and high in accuracy.

Description

Technical Field

[0001] The present application relates to the technical field of hearing protector research, and in particular to a method for detecting the personal sound attenuation value of a hearing protector. Background Art

[0002] Long-term exposure to high noise levels can cause permanent, irreversible hearing loss. In the field of occupational health, hearing loss caused by occupational noise is one of the most common occupational hazards. To protect workers' hearing health, hearing protectors (earplugs, earmuffs, etc.) are widely used protective equipment, and personal sound attenuation is an important performance indicator for evaluating the effectiveness of hearing protectors.

[0003] Because each person's ear canal structure is different, the actual individual sound attenuation produced by the same hearing protector when worn in different people's ear canals can vary significantly. This actual individual sound attenuation can differ significantly from the nominal sound attenuation value specified by the hearing protector manufacturer. The individual sound attenuation value of the test subject after wearing the hearing protector on-site is a crucial parameter for evaluating the individual suitability of the hearing protector, and ensuring measurement accuracy is crucial.

[0004] Traditional methods for measuring personal sound attenuation typically use a tube-based sound transmission method. Specifically, a tube is placed in the ear canal, followed by two microphones and two sensors. Both microphones are placed outside the ear, and the subject wears a hearing protector in each ear. Each hearing protector has a hole drilled in the middle and passes through a tube. One end of the tube extends into the ear canal, while the other end extends outside the ear and connects to a microphone outside the ear. The outer diameter of the microphone matches the tube. During measurement, sound from inside the ear canal is transmitted through the tube to the outside of the ear canal for measurement. A second microphone, not connected to the tube, is also placed outside the ear canal and is referred to as the reference microphone. The sound attenuation of the hearing protector is then calculated as the difference between the sound pressure level of the reference microphone and the sound pressure level of the microphone connected to the tube. Traditional methods for measuring personal sound attenuation not only require destructive testing of the hearing protector, but also require difficult to manually determine the accuracy of the hole drilling. Measurement accuracy also depends on the sound insulation of the tube itself, which is affected by the tube material. Therefore, traditional methods for measuring personal sound attenuation have high measurement uncertainty and cannot guarantee accuracy. Summary of the Invention

[0005] Based on this, it is necessary to provide a method for detecting the personal sound attenuation value of a hearing protector to address the problem that the traditional method for detecting the personal sound attenuation value of a hearing protector has large measurement uncertainty and cannot guarantee accuracy.

[0006] The present application provides a method for detecting the personal sound attenuation value of a hearing protector, the method comprising:

[0007] In a test environment where neither ear is wearing a hearing protector, control the sound source to emit a first test sound;

[0008] Obtaining original waveforms collected by each of the four microphones, and obtaining a left ear canal transfer function and a right ear canal transfer function based on the spectral sound pressure levels of the original waveforms collected by each of the four microphones; setting a microphone in the left ear canal, outside the left ear, in the right ear canal, and outside the right ear;

[0009] Under the test environment where the positions of the microphones remain unchanged and both ears are wearing hearing protectors, control the sound source to emit a second test sound;

[0010] Obtaining original waveforms collected by each of the four microphones, compensating the spectral sound pressure levels of the original waveforms collected by each of the four microphones using the left ear canal transfer function and the right ear canal transfer function to obtain the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value;

[0011] The left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value are calculated based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value.

[0012] Furthermore, the obtaining of original waveforms collected by the four microphones and obtaining a left ear canal transfer function and a right ear canal transfer function according to the spectral sound pressure levels of the original waveforms collected by the four microphones include:

[0013] Acquire an original waveform collected by a first microphone in the ear canal of the left ear, an original waveform collected by a second microphone outside the left ear, an original waveform collected by a third microphone in the ear canal of the right ear, and an original waveform collected by a fourth microphone outside the right ear;

[0014] Calculating a first equivalent spectral sound pressure level based on an original waveform collected by a first microphone in the ear canal of the left ear, calculating a second equivalent spectral sound pressure level based on an original waveform collected by a second microphone outside the left ear, calculating a third equivalent spectral sound pressure level based on an original waveform collected by a third microphone in the ear canal of the right ear, and calculating a fourth equivalent spectral sound pressure level based on an original waveform collected by a fourth microphone outside the right ear;

[0015] The difference between the second equivalent spectrum sound pressure level and the first equivalent spectrum sound pressure level is used as the left ear canal transfer function;

[0016] The difference between the fourth equivalent spectrum sound pressure level and the third equivalent spectrum sound pressure level is taken as the right ear canal transfer function.

[0017] Furthermore, the method of obtaining the original waveforms collected by each of the four microphones and compensating the spectral sound pressure levels of the original waveforms collected by each of the four microphones using the left ear canal transfer function and the right ear canal transfer function to obtain the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value includes:

[0018] Acquire an original waveform collected by a first microphone in the ear canal of the left ear, an original waveform collected by a second microphone outside the left ear, an original waveform collected by a third microphone in the ear canal of the right ear, and an original waveform collected by a fourth microphone outside the right ear;

[0019] A fifth equivalent spectral sound pressure level is calculated based on the original waveform collected by the first microphone in the ear canal of the left ear, a sixth equivalent spectral sound pressure level is calculated based on the original waveform collected by the second microphone outside the left ear, a seventh equivalent spectral sound pressure level is calculated based on the original waveform collected by the third microphone in the ear canal of the right ear, and an eighth equivalent spectral sound pressure level is calculated based on the original waveform collected by the fourth microphone outside the right ear;

[0020] Calculating the difference between the sixth equivalent spectrum sound pressure level and the fifth equivalent spectrum sound pressure level, and subtracting the left ear canal transfer function from the difference between the sixth equivalent spectrum sound pressure level and the fifth equivalent spectrum sound pressure level to obtain a result as the attenuation value of the left ear hearing protector;

[0021] The difference between the eighth equivalent spectrum sound pressure level and the seventh equivalent spectrum sound pressure level is calculated, and the right ear canal transfer function is subtracted from the difference between the eighth equivalent spectrum sound pressure level and the seventh equivalent spectrum sound pressure level to obtain a result as the attenuation value of the right ear hearing protector.

[0022] Furthermore, the calculation of the left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value includes:

[0023] Substitute the attenuation value of the left ear hearing protector into the calculation formula of the A-weighted noise sound attenuation statistical value to calculate the A-weighted noise sound attenuation statistical value of the left ear. The calculation formula of the A-weighted noise sound attenuation statistical value is:

[0024]

[0025] Among them, FAES A is the A-weighted noise attenuation statistic, n is the serial number of the industrial noise spectrum, k is the serial number of each frequency point in the 1 / 1 OCT octave, A k is the A-weighted attenuation value of each frequency point in the 1 / 1 OCT octave, L n,k is the spectral sound pressure level corresponding to the kth frequency point and the nth industrial noise spectrum in the 1 / 1 OCT octave band, L atten,k is the sound attenuation value of the hearing protector;

[0026] Set the weight coefficient factor;

[0027] Substitute the weight coefficient factor and the A-weighted noise attenuation statistical value of the left ear into the calculation formula of the personal sound attenuation value to obtain the personal sound attenuation value of the left ear. The calculation formula of the personal sound attenuation value is:

[0028]

[0029] Among them, PAR x is the personal sound attenuation value, x is the weight coefficient factor, α x is the weight coefficient, FAES A is the statistical value of A-weighted noise attenuation, is the comprehensive measurement uncertainty of the A-weighted noise attenuation statistical value.

[0030] Furthermore, the calculating of the left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value further includes:

[0031] Substitute the right ear hearing protector attenuation value as the hearing protector sound attenuation value into the calculation formula of the A-weighted noise sound attenuation statistical value to calculate the A-weighted noise sound attenuation statistical value of the right ear. The calculation formula of the A-weighted noise sound attenuation statistical value is:

[0032]

[0033] Among them, FAES A is the A-weighted noise attenuation statistic, n is the serial number of the industrial noise spectrum, k is the serial number of each frequency point in the 1 / 1 OCT octave, A k is the A-weighted attenuation value of each frequency point in the 1 / 1 OCT octave, L n,k is the spectral sound pressure level corresponding to the kth frequency point and the nth industrial noise spectrum in the 1 / 1 OCT octave band, L atten,k is the sound attenuation value of the hearing protector;

[0034] Set the weight coefficient factor;

[0035] Substitute the weight coefficient factor and the A-weighted noise attenuation statistical value of the right ear into the calculation formula of the personal sound attenuation value to obtain the personal sound attenuation value of the right ear. The calculation formula of the personal sound attenuation value is:

[0036]

[0037] Among them, PAR x is the personal sound attenuation value, x is the weight coefficient factor, α x is the weight coefficient, FAES A is the statistical value of A-weighted noise attenuation, is the comprehensive measurement uncertainty of the A-weighted noise attenuation statistical value.

[0038] Furthermore, the calculation of the left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value includes:

[0039] The smaller value between the attenuation value of the left ear hearing protector and the attenuation value of the right ear hearing protector is used as the binaural integrated sound attenuation value;

[0040] Substitute the binaural comprehensive sound attenuation value as the hearing protector sound attenuation value into the calculation formula of the A-weighted noise sound attenuation statistical value to calculate the A-weighted noise sound attenuation statistical value of the binaural A-weighted noise. The calculation formula of the A-weighted noise sound attenuation statistical value is:

[0041]

[0042] Among them, FAES A is the A-weighted noise attenuation statistic, n is the serial number of the industrial noise spectrum, k is the serial number of each frequency point in the 1 / 1 OCT octave, A k is the A-weighted attenuation value of each frequency point in the 1 / 1 OCT octave, L n,k is the spectral sound pressure level corresponding to the kth frequency point and the nth industrial noise spectrum in the 1 / 1 OCT octave band, L atten,k is the sound attenuation value of the hearing protector;

[0043] Set the weight coefficient factor;

[0044] Substitute the weight coefficient factor and the A-weighted noise attenuation statistics of both ears into the calculation formula of the personal sound attenuation value to obtain the personal sound attenuation value of both ears. The calculation formula of the personal sound attenuation value is:

[0045]

[0046] Among them, PAR x is the personal sound attenuation value, x is the weight coefficient factor, α x is the weight coefficient, FAES A is the statistical value of A-weighted noise attenuation, is the comprehensive measurement uncertainty of the A-weighted noise attenuation statistical value.

[0047] Furthermore, the first test sound is a broadband white noise signal or a broadband pink noise signal, and the second test sound is a broadband white noise signal or a broadband pink noise signal.

[0048] Furthermore, the straight-line distance between the sound source and the physical center of the subject's head is less than or equal to a preset distance, which is 1 meter.

[0049] Furthermore, the microphone arranged outside the left ear is fixed at a fixed position outside the left ear by a fixing bracket, and the microphone arranged outside the right ear is fixed at a fixed position outside the right ear by a fixing bracket.

[0050] Furthermore, the microphone disposed in the ear canal of the left ear and the microphone disposed in the ear canal of the right ear are both connected via a flexible sound-transmitting wire and a fixed bracket.

[0051] The present application relates to a method for detecting the personal sound attenuation value of a hearing protector. A microphone is set in the ear canal of the left ear, outside the left ear, inside the ear canal of the right ear, and outside the right ear. A first test sound is emitted in a test environment where neither ear is wearing a hearing protector. The left ear canal transfer function and the right ear canal transfer function are obtained based on the spectral sound pressure level of the original waveform collected by each of the four microphones. These transfer functions can be used in subsequent calculations of sound attenuation to eliminate the ear canal effects caused by the frequency response differences of the microphones themselves and the differences in the positions of the microphones during measurement. The present application also controls the sound source to emit a second test sound in a test environment where both ears are wearing hearing protectors, and the spectral sound pressure level unblocked by the hearing protector is obtained from the results collected by the microphone outside the ear canal. The spectral sound pressure level blocked by the hearing protector is obtained from the results collected by the microphone inside the ear canal. The sound attenuation caused by wearing the hearing protector is obtained by subtracting the spectral sound pressure levels measured by the two microphones, thereby obtaining the personal sound attenuation value. After the measurement is completed, the personal sound attenuation value and the hearing protector model can be saved in the database accordingly, which will help users to screen or improve hearing protectors in the future. Since the sound attenuation is compensated by the transfer function, the uncertainty of the measured personal sound attenuation value is small and the accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a flow chart of a method for detecting the personal sound attenuation value of a hearing protector provided in one embodiment of the present application.

[0053] Figure 2 This is a structural diagram of a system for detecting personal sound attenuation values of hearing protectors provided in one embodiment of the present application.

[0054] Figure 3 This is a line diagram of four microphones in a system for detecting personal sound attenuation values of hearing protectors provided in one embodiment of the present application.

[0055] Figure 4 This is a physical schematic diagram of four microphones in a system for detecting personal sound attenuation values of a hearing protector provided in one embodiment of the present application.

[0056] Figure 5 This is a diagram of the left ear usage status of the hearing protector personal sound attenuation value detection system provided by one embodiment of the present application.

[0057] Reference numerals:

[0058] 100-data acquisition equipment; 200-sound source; 300-hearing protector; 400-microphone;

[0059] 410 - first microphone; 420 - second microphone; 430 - third microphone;

[0060] 440 - fourth microphone; 500 - fixed bracket; 510 - first bracket; 520 - second bracket. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0062] The present application provides a method for detecting the personal sound attenuation value of a hearing protector. It should be noted that the method for detecting the personal sound attenuation value of a hearing protector provided in the present application is applicable to any model, type, and brand of hearing protectors, including but not limited to earmuffs and earplugs.

[0063] Furthermore, the method for detecting the individual sound attenuation value of a hearing protector provided herein does not limit its execution entity. Alternatively, the method for detecting the individual sound attenuation value of a hearing protector provided herein may be executed by a system for detecting the individual sound attenuation value of a hearing protector. Specifically, the method for detecting the individual sound attenuation value of a hearing protector provided herein may be executed by the data acquisition device 100 in the system for detecting the individual sound attenuation value of the hearing protector.

[0064] like Figure 1 As shown, in one embodiment of the present application, the method for detecting the personal sound attenuation value of the hearing protector includes the following steps S100 to S500:

[0065] S100: In a test environment where neither ear is wearing a hearing protector, a sound source is controlled to emit a first test sound.

[0066] At step S200 , original waveforms collected by each of the four microphones 400 are obtained, and the left ear canal transfer function and the right ear canal transfer function are obtained based on the spectral sound pressure levels of the original waveforms collected by each of the four microphones 400 . A microphone 400 is provided in each of the left ear canal, the left ear, the right ear canal, and the right ear.

[0067] S300 , in a test environment where the positions of the microphones 400 are kept unchanged and both ears are wearing hearing protectors, the sound source 200 is controlled to emit a second test sound.

[0068] S400 , obtaining the original waveforms collected by the four microphones 400 , and compensating the spectral sound pressure levels of the original waveforms collected by the four microphones 400 using the left ear canal transfer function and the right ear canal transfer function to obtain the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value.

[0069] S500 , calculating a left ear personal sound attenuation value, a right ear personal sound attenuation value, and a binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value.

[0070] Specifically, the four microphones 400 are divided into two groups, each group of microphones is worn on one ear, and each group of microphones includes two microphones 400. During measurement, one microphone 400 in a group of microphones is placed in the ear canal, and the other microphone 400 is placed outside the ear.

[0071] S200 and S400 are two similar measurement processes. In each measurement process, the two microphones 400 of each ear are located inside the ear canal and outside the ear respectively, and the sound pressure levels of the inner and outer ears are measured simultaneously.

[0072] The difference is:

[0073] S200 is measured without wearing hearing protectors 300 on both ears.

[0074] S400 is when wearing a set of microphones, first put one microphone 400 into the ear canal, then put on the hearing protector 300, and then put the other microphone 400 outside the ear canal through the fixing bracket 500. The same is true for the other set of microphones, which will not be repeated here.

[0075] In this embodiment, a microphone 400 is disposed in the ear canal of the left ear, outside the left ear, in the ear canal of the right ear, and outside the right ear. A first test sound is emitted in a test environment in which neither ear is wearing a hearing protector 300. The ear canal transfer function of the left ear and the ear canal transfer function of the right ear are obtained based on the spectral sound pressure levels of the original waveforms collected by each of the four microphones 400. These transfer functions can be used in the subsequent calculation of sound attenuation to eliminate the ear canal influence caused by the frequency response differences of the microphones 400 themselves and the differences in the positions of the microphones 400 during measurement. This application also controls the sound source 200 to emit a second test sound in a test environment where the positions of the microphones 400 remain unchanged and both ears are wearing hearing protectors 300. The sound pressure level of the spectrum that is not blocked by the hearing protector 300 is obtained through the collection results of the microphone 400 outside the ear canal, and the sound pressure level of the spectrum that is blocked by the hearing protector 300 is obtained through the collection results of the microphone 400 inside the ear canal. The sound attenuation produced by wearing the hearing protector 300 is obtained by subtracting the sound pressure levels measured by the two microphones 400, and then the personal sound attenuation value is obtained. After the measurement is completed, the personal sound attenuation value and the hearing protector 300 model can be saved to the database accordingly, which will help users to screen the hearing protector 300 or improve the hearing protector 300 in the future. Since the sound attenuation is compensated by the transfer function, the uncertainty of the measured personal sound attenuation value is small and the accuracy is high.

[0076] In one embodiment of the present application, S200 includes obtaining the original waveforms collected by each of the four microphones 400, and obtaining the left ear canal transfer function and the right ear canal transfer function based on the spectral sound pressure levels of the original waveforms collected by each of the four microphones 400, including:

[0077] S210, obtaining the original waveform collected by the first microphone 410 in the left ear canal, the original waveform collected by the second microphone 420 outside the left ear, the original waveform collected by the third microphone 430 in the right ear canal, and the original waveform collected by the fourth microphone 440 outside the right ear.

[0078] S220, calculate a first equivalent spectral sound pressure level based on the original waveform collected by the first microphone 410 in the ear canal of the left ear, calculate a second equivalent spectral sound pressure level based on the original waveform collected by the second microphone 420 outside the left ear, calculate a third equivalent spectral sound pressure level based on the original waveform collected by the third microphone 430 in the ear canal of the right ear, and calculate a fourth equivalent spectral sound pressure level based on the original waveform collected by the fourth microphone 440 outside the right ear.

[0079] S230: Taking the difference between the second equivalent spectrum sound pressure level and the first equivalent spectrum sound pressure level as the left ear canal transfer function.

[0080] S240: Taking the difference between the fourth equivalent spectrum sound pressure level and the third equivalent spectrum sound pressure level as the right ear canal transfer function.

[0081] Specifically, the frequency response differences of microphone 400 itself and the ear canal effects caused by differences in the position of microphone 400 during measurement can affect the measurement results. Therefore, a transfer function for the frequency response differences between microphones 400 and the ear canal effects is first obtained during step S200. This allows automatic compensation and correction of the measurement results during the subsequent measurement step S400 to eliminate the ear canal effects caused by the frequency response differences of microphone 400 itself and the position differences of microphone 400 during measurement.

[0082] First, the microphone 400, along with the fixing bracket 500, is worn on the subject's head. The four microphones 400 are placed inside and outside the ear canals of the left and right ears, respectively. Hearing protectors 300 are not required at this time. The data acquisition device 100 then controls the sound source 200 to emit a first test sound. The data acquisition device 100 and sound source 200 are connected via a wireless network, and the data acquisition device 100 controls the sound source 200 to emit the first test sound. The sound source 200 emits a broadband white noise or pink noise signal. The data acquisition device 100 then synchronously collects the original waveforms of the four channels and calculates the equivalent spectral sound pressure level.

[0083] Calculate the left ear canal transfer function according to Formula 1.

[0084] H L,k =L L_out,k -L L_in,k Formula 1.

[0085] Calculate the right ear canal transfer function according to Formula 2.

[0086] H R,k =L R_out,k -L R_in,k Formula 2.

[0087] Among them, R represents the right ear, L represents the left ear, in represents the inside of the ear canal, out represents the outside of the ear, and k is the serial number of each frequency point in the 1 / 1 OCT octave band. L,k is the left ear canal transfer function, H R,k is the right ear canal transfer function, L L_in,k is the first equivalent spectrum sound pressure level, L L_out,k is the second equivalent spectrum sound pressure level, L R_in,k is the third equivalent spectrum sound pressure level, L R_out,k is the fourth equivalent spectrum sound pressure level.

[0088] In this embodiment, a first test sound is emitted in a test environment where neither ear is wearing a hearing protector 300. The left ear canal transfer function and the right ear canal transfer function are obtained based on the spectral sound pressure levels of the original waveforms collected by each of the four microphones 400. These transfer functions can be used in the subsequent calculation of sound attenuation to eliminate the ear canal effects caused by the frequency response differences of the microphones 400 themselves and the differences in the positions of the microphones 400 during measurement.

[0089] In one embodiment of the present application, S400 includes obtaining the original waveforms collected by each of the four microphones 400, compensating the spectral sound pressure levels of the original waveforms collected by each of the four microphones 400 using the left ear canal transfer function and the right ear canal transfer function to obtain the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value, including:

[0090] S410, obtaining the original waveform collected by the first microphone 410 in the left ear canal, the original waveform collected by the second microphone 420 outside the left ear, the original waveform collected by the third microphone 430 in the right ear canal, and the original waveform collected by the fourth microphone 440 outside the right ear.

[0091] S420, calculate the fifth equivalent spectral sound pressure level based on the original waveform collected by the first microphone 410 in the ear canal of the left ear, calculate the sixth equivalent spectral sound pressure level based on the original waveform collected by the second microphone 420 outside the left ear, calculate the seventh equivalent spectral sound pressure level based on the original waveform collected by the third microphone 430 in the ear canal of the right ear, and calculate the eighth equivalent spectral sound pressure level based on the original waveform collected by the fourth microphone 440 outside the right ear.

[0092] S430 , calculating the difference between the sixth equivalent spectrum sound pressure level and the fifth equivalent spectrum sound pressure level, and subtracting the left ear canal transfer function from the difference between the sixth equivalent spectrum sound pressure level and the fifth equivalent spectrum sound pressure level to obtain a result as the attenuation value of the left ear hearing protector.

[0093] S440 , calculating the difference between the eighth equivalent spectrum sound pressure level and the seventh equivalent spectrum sound pressure level, and subtracting the right ear canal transfer function from the difference between the eighth equivalent spectrum sound pressure level and the seventh equivalent spectrum sound pressure level to obtain a result as the attenuation value of the right ear hearing protector.

[0094] Specifically, S410 to S440 are the measurement process after the hearing protector 300 is worn on both ears.

[0095] First, the test subject wears the microphone 400 along with the mounting bracket 500 on their head, placing the two microphones 400 in the ear canals of their left and right ears, respectively. The test subject then wears the hearing protector 300 for both ears. Finally, the two microphones 400 are secured to the outside of their left and right ears, completing the test. The data acquisition device 100 then controls the sound source 200 to emit a second test sound. The data acquisition device 100 and sound source 200 are connected via a wireless network, and the data acquisition device 100 controls the sound source 200 to emit the second test sound. The sound source 200 emits a broadband white noise or pink noise signal. At this point, the data acquisition device 100 synchronously collects the original waveforms of the four channels and calculates the equivalent spectral sound pressure level.

[0096] The attenuation value of the left ear hearing protector is then calculated according to Formula 3.

[0097] L L_atten,k =L′ L_out,k -L′ L_in,k -H L,k Formula 3.

[0098] The attenuation value of the right ear hearing protector is then calculated according to Formula 4.

[0099] L R_atten,k =L′ R_out,k -L′ R_in,k -H R,k Formula 4.

[0100] Among them, R represents the right ear, L represents the left ear, in represents the inside of the ear canal, out represents the outside of the ear, and k is the serial number of each frequency point in the 1 / 1 OCT octave band. L_atten,k is the attenuation value of the left ear hearing protector. R_atten,k is the attenuation value of the right ear hearing protector. L,k is the left ear canal transfer function, H R,k is the right ear canal transfer function, L′ L_in,k is the fifth equivalent spectrum sound pressure level, L′ L_out,k is the sixth equivalent spectrum sound pressure level, L′ R_in,k is the seventh equivalent spectrum sound pressure level, L′ R_out,k It is the eighth equivalent spectrum sound pressure level.

[0101] In this embodiment, the spectral sound pressure level blocked by the hearing protector 300 is obtained by collecting the results of the microphone 400 in the ear canal. The sound attenuation caused by wearing the hearing protector 300 is obtained by subtracting the spectral sound pressure levels measured by the two microphones 400, and then the personal sound attenuation value is obtained. Since the sound attenuation is compensated by the transfer function, the uncertainty of the measured personal sound attenuation value is small and the accuracy is high.

[0102] In one embodiment of the present application, S500 includes calculating the left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value, including:

[0103] S511 , substituting the attenuation value of the left ear hearing protector as the hearing protector sound attenuation value into the calculation formula of the A-weighted noise sound attenuation statistical value to calculate the A-weighted noise sound attenuation statistical value of the left ear. The calculation formula of the A-weighted noise sound attenuation statistical value is shown in Formula 5.

[0104]

[0105] Among them, FAES A is the A-weighted noise attenuation statistic, n is the serial number of the industrial noise spectrum, k is the serial number of each frequency point in the 1 / 1 OCT octave, A k is the A-weighted attenuation value of each frequency point in the 1 / 1 OCT octave, L n,k is the spectral sound pressure level corresponding to the kth frequency point and the nth industrial noise spectrum in the 1 / 1 OCT octave band, L atten,k is the sound attenuation value of the hearing protector.

[0106] S512: Set the weight coefficient factor.

[0107] S513 , substituting the weight coefficient factor and the A-weighted noise attenuation statistical value of the left ear into a calculation formula of the personal sound attenuation value to obtain the personal sound attenuation value of the left ear. The calculation formula of the personal sound attenuation value is shown in Formula 6.

[0108]

[0109] Among them, PAR x is the personal sound attenuation value, x is the weight coefficient factor, α x is the weight coefficient, FAES A is the statistical value of A-weighted noise attenuation, is the comprehensive measurement uncertainty of the A-weighted noise attenuation statistical value.

[0110] Specifically, x is a weight coefficient factor, and the value of x is a value between 0-100%. x will affect the weight coefficient α at different percentages. x When x takes 50%, α x The value of PAR is 0. x The value is equal to FAES A value.

[0111] The industrial noise spectrum can be selected from the noise spectrum database of the National Institute for Occupational Safety and Health (NIOSH).

[0112] This embodiment calculates the personal sound attenuation value of the left ear, so the attenuation value of the hearing protector of the left ear is substituted into Formula 5.

[0113] In one embodiment of the present application, S500 further includes calculating the left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value, further including:

[0114] S521 , substituting the right ear hearing protector attenuation value as the hearing protector sound attenuation value into the calculation formula of the A-weighted noise sound attenuation statistical value to calculate the A-weighted noise sound attenuation statistical value of the right ear. The calculation formula of the A-weighted noise sound attenuation statistical value is shown in Formula 5.

[0115] S522: Set the weight coefficient factor.

[0116] S523 , substituting the weight coefficient factor and the A-weighted noise attenuation statistical value of the right ear into a calculation formula for the personal sound attenuation value to obtain the personal sound attenuation value of the right ear. The calculation formula for the personal sound attenuation value is shown in Formula 6.

[0117] Specifically, in this embodiment, since Formula 5 and Formula 6 used are exactly the same as Formula 5 and Formula 6 used in the embodiments of S511 to S513, except that the numerical values substituted are different, for the sake of brevity, the specific forms of Formula 5 and Formula 6 are not repeated here, and the above content has mentioned them.

[0118] This embodiment calculates the personal sound attenuation value of the right ear, so the attenuation value of the hearing protector of the right ear is substituted into Formula 5.

[0119] In one embodiment of the present application, S500 further includes calculating the left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value, further including:

[0120] S531: The smaller one of the attenuation value of the left ear hearing protector and the attenuation value of the right ear hearing protector is used as the binaural integrated sound attenuation value.

[0121] S532: Substitute the binaural integrated sound attenuation value as the hearing protector sound attenuation value into the calculation formula of the A-weighted noise sound attenuation statistical value to calculate the A-weighted noise sound attenuation statistical value of the binaural A-weighted noise. The calculation formula of the A-weighted noise sound attenuation statistical value is shown in Formula 5.

[0122] S533: Set the weight coefficient factor.

[0123] S534 , substituting the weight coefficient factor and the A-weighted noise attenuation statistical value of both ears into a calculation formula of the personal sound attenuation value to obtain the personal sound attenuation value of both ears. The calculation formula of the personal sound attenuation value is shown in Formula 6.

[0124] Specifically, in this embodiment, since Formula 5 and Formula 6 used are exactly the same as Formula 5 and Formula 6 used in the embodiments of S511 to S513, except that the numerical values substituted are different, for the sake of brevity, the specific forms of Formula 5 and Formula 6 are not repeated here, and the above content has mentioned them.

[0125] This embodiment calculates the personal sound attenuation values of both ears, so the smaller one of the attenuation value of the left ear hearing protector and the attenuation value of the right ear hearing protector is substituted into Formula 5.

[0126] In this embodiment, the individual sound attenuation values for both ears are calculated by substituting the smaller of the attenuation value of the left ear hearing protector and the attenuation value of the right ear hearing protector into Formula 5. We generally hope that the attenuation value of the hearing protector 300 is as large as possible, because the larger the attenuation value, the better the sound insulation quality of the hearing protector 300. However, we select the smaller of the attenuation value of the left ear hearing protector and the attenuation value of the right ear hearing protector to substitute into Formulas 5 and 6 to calculate the individual sound attenuation values for both ears. This is to make the individual sound attenuation values for both ears more consistent with unfavorable extreme situations, so that the confidence of the individual sound attenuation values for both ears finally calculated is higher.

[0127] In one embodiment of the present application, the first test sound is a broadband white noise signal or a broadband pink noise signal, and the second test sound is a broadband white noise signal or a broadband pink noise signal.

[0128] Specifically, in order to control variables, the first test sound and the second test sound may be completely identical test sounds.

[0129] In this embodiment, by setting the test sound to a wide-band white noise signal or a wide-band pink noise signal, the full-band test can be completed at one time.

[0130] In one embodiment of the present application, the straight-line distance between the sound source 200 and the physical center of the subject's head is less than or equal to a preset distance, which is 1 meter.

[0131] Specifically, the straight-line distance between the sound source 200 and the physical center of the subject's head should not be too large, with 1 meter being a suitable distance. In acoustic testing, 1 meter ensures that all test frequencies are in a far-field environment, avoiding near-field testing, where the sound field is more complex and less conducive to testing.

[0132] In this embodiment, by setting the straight-line distance between the sound source 200 and the physical center of the subject's head to be less than or equal to a preset distance, the problem of inaccurate test results caused by an inappropriate distance between the sound source 200 and the subject's ear is avoided.

[0133] In one embodiment of the present application, the microphone 400 disposed outside the left ear is fixed at a fixed position outside the left ear by a fixing bracket 500, and the microphone 400 disposed outside the right ear is fixed at a fixed position outside the right ear by a fixing bracket 500.

[0134] Specifically, the left ear and the right ear can use the same fixing bracket 500 to fix the microphone 400 disposed outside the ear, or two different fixing brackets 500 can be used to fix the microphone 400 outside the left ear and the microphone 400 outside the right ear respectively. Figure 5 As shown, Figure 5 The embodiment uses a fixing bracket 500 similar to the main body of the sports earphones, which is then hung around the neck of the tester and fixed with Velcro or tape, without using two different fixing brackets 500.

[0135] Of course, the fixing bracket 500 may also include two different brackets, such as Figure 3 and Figure 4 As shown, the fixed bracket 500 includes a first bracket 510 and a second bracket 520 , and the two brackets correspond to different ears respectively, that is, the two brackets are connected to different microphones 400 respectively.

[0136] In this embodiment, the microphone 400 outside the left ear and the microphone 400 outside the right ear are fixed by providing a fixing bracket 500, so that the position of the microphone 400 outside the ear will not change easily, and will not cause jitter influence on the test results.

[0137] In one embodiment of the present application, the microphone 400 disposed in the ear canal of the left ear and the microphone 400 disposed in the ear canal of the right ear are both connected via a flexible sound-transmitting wire and a fixing bracket 500 .

[0138] Specifically, the wire material capable of transmitting sound may be made of copper.

[0139] In this embodiment, when wearing a set of microphones, one microphone 400 is first placed in the ear canal, then the hearing protector 300 is put on, and then the other microphone 400 is placed outside the ear canal through the fixing bracket 500. By wearing the microphone 400 and the hearing protector 300 in this way, the microphone 400 set in the ear canal of the left ear and the microphone 400 set in the ear canal of the right ear are both connected to the fixing bracket 500 through a flexible and sound-transmitting wire, so that during the measurement of the personal sound attenuation value, there is no need to make destructive holes in the hearing protector 300, thereby protecting the integrity of the hearing protector 300 and saving testing costs.

[0140] Optionally, after the measurement is completed, the individual's sound attenuation value and the hearing protector 300 type (model and other nameplate information) can be saved to a database. Subsequently, historical measurement data can be viewed by hearing protector 300 type or tester, and a suitability report for the hearing protector 300 can be generated to help users select or improve hearing protectors 300.

[0141] The present application also provides a system for detecting the personal sound attenuation value of a hearing protector.

[0142] In one embodiment of the present application, Figure 2 As shown, the hearing protector personal sound attenuation value detection system includes a data acquisition device 100, a sound source 200, a hearing protector 300, a microphone 400 and a fixing bracket 500. Figure 3 and Figure 4 As shown, the microphone 400 includes a first microphone 410 , a second microphone 420 , a third microphone 430 and a fourth microphone 440 .

[0143] The sound source 200 is in communication connection with the data acquisition device 100. The microphone 400 is in communication connection with the data acquisition device 100.

[0144] Specifically, the fixing bracket 500 may include a first bracket 510 and a second bracket 520. The first microphone 410 extends into the left ear canal, and then the first microphone 410 is fixedly connected to the first bracket 510 through a flexible and sound-transmitting wire. The second microphone 420 is arranged outside the left ear and is fixed to a fixed position outside the left ear by the first bracket 510. Figure 5 shown.

[0145] Similarly, Figure 5The placement of the third and fourth microphones 430, 440 is not shown, but the placement of the third and fourth microphones 430, 440 is similar to that of the first and second microphones 410, 420. The third microphone 430 extends into the right ear canal and is then fixedly connected to the second bracket 520 via a flexible, sound-transmitting wire. The fourth microphone 440 is located outside the left ear and is secured to a fixed position outside the right ear by the second bracket 520.

[0146] The various technical features of the above-described embodiments can be combined arbitrarily, and the execution order of the method steps is not restricted. In order to make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0147] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for detecting the personal sound attenuation value of a hearing protector, characterized in that: The method for detecting the personal sound attenuation value of the hearing protector comprises: In a test environment where neither ear is wearing a hearing protector, control the sound source to emit a first test sound; Obtaining original waveforms collected by each of the four microphones, and obtaining a left ear canal transfer function and a right ear canal transfer function based on the spectral sound pressure levels of the original waveforms collected by each of the four microphones; setting a microphone in the left ear canal, outside the left ear, in the right ear canal, and outside the right ear; Under the test environment where the positions of the microphones remain unchanged and both ears are wearing hearing protectors, control the sound source to emit a second test sound; Obtaining original waveforms collected by each of the four microphones, compensating the spectral sound pressure levels of the original waveforms collected by each of the four microphones using the left ear canal transfer function and the right ear canal transfer function to obtain the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value; The left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value are calculated based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value.

2. The method for detecting the personal sound attenuation value of a hearing protector according to claim 1, characterized in that: The step of obtaining the original waveforms collected by the four microphones and obtaining the left ear canal transfer function and the right ear canal transfer function according to the spectral sound pressure levels of the original waveforms collected by the four microphones includes: Acquire an original waveform collected by a first microphone in the ear canal of the left ear, an original waveform collected by a second microphone outside the left ear, an original waveform collected by a third microphone in the ear canal of the right ear, and an original waveform collected by a fourth microphone outside the right ear; Calculating a first equivalent spectral sound pressure level based on an original waveform collected by a first microphone in the ear canal of the left ear, calculating a second equivalent spectral sound pressure level based on an original waveform collected by a second microphone outside the left ear, calculating a third equivalent spectral sound pressure level based on an original waveform collected by a third microphone in the ear canal of the right ear, and calculating a fourth equivalent spectral sound pressure level based on an original waveform collected by a fourth microphone outside the right ear; The difference between the second equivalent spectrum sound pressure level and the first equivalent spectrum sound pressure level is used as the left ear canal transfer function; The difference between the fourth equivalent spectrum sound pressure level and the third equivalent spectrum sound pressure level is taken as the right ear canal transfer function.

3. The method for detecting the personal sound attenuation value of a hearing protector according to claim 2, characterized in that: The method of obtaining the original waveforms collected by the four microphones, compensating the spectral sound pressure levels of the original waveforms collected by the four microphones using the left ear canal transfer function and the right ear canal transfer function to obtain the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value includes: Acquire an original waveform collected by a first microphone in the ear canal of the left ear, an original waveform collected by a second microphone outside the left ear, an original waveform collected by a third microphone in the ear canal of the right ear, and an original waveform collected by a fourth microphone outside the right ear; A fifth equivalent spectral sound pressure level is calculated based on the original waveform collected by the first microphone in the ear canal of the left ear, a sixth equivalent spectral sound pressure level is calculated based on the original waveform collected by the second microphone outside the left ear, a seventh equivalent spectral sound pressure level is calculated based on the original waveform collected by the third microphone in the ear canal of the right ear, and an eighth equivalent spectral sound pressure level is calculated based on the original waveform collected by the fourth microphone outside the right ear; Calculating the difference between the sixth equivalent spectrum sound pressure level and the fifth equivalent spectrum sound pressure level, and subtracting the left ear canal transfer function from the difference between the sixth equivalent spectrum sound pressure level and the fifth equivalent spectrum sound pressure level to obtain a result as the attenuation value of the left ear hearing protector; The difference between the eighth equivalent spectrum sound pressure level and the seventh equivalent spectrum sound pressure level is calculated, and the right ear canal transfer function is subtracted from the difference between the eighth equivalent spectrum sound pressure level and the seventh equivalent spectrum sound pressure level to obtain a result as the attenuation value of the right ear hearing protector.

4. The method for detecting the personal sound attenuation value of a hearing protector according to claim 3, characterized in that: The calculating of the left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value includes: Substitute the attenuation value of the left ear hearing protector as the hearing protector sound attenuation value into the calculation formula of the A-weighted noise sound attenuation statistical value to calculate the A-weighted noise sound attenuation statistical value of the left ear. The calculation formula of the A-weighted noise sound attenuation statistical value is: Wherein, FAESA is the A-weighted noise attenuation statistic, n is the serial number of the industrial noise spectrum, k is the serial number of each frequency point in the 1 / 1OCT octave, Ak is the A-weighted attenuation value of each frequency point in the 1 / 1OCT octave, Ln,k is the spectral sound pressure level corresponding to the k-th frequency point in the 1 / 1OCT octave and the n-th industrial noise spectrum, and Latten,k is the sound attenuation value of the hearing protector; Set the weight coefficient factor; Substitute the weight coefficient factor and the A-weighted noise attenuation statistical value of the left ear into the calculation formula of the personal sound attenuation value to obtain the personal sound attenuation value of the left ear. The calculation formula of the personal sound attenuation value is: Among them, PARx is the personal sound attenuation value, x is the weight coefficient factor, αx is the weight coefficient, FAESA is the A-weighted noise sound attenuation statistical value, is the comprehensive measurement uncertainty of the A-weighted noise attenuation statistical value.

5. The method for detecting the personal sound attenuation value of a hearing protector according to claim 4, characterized in that: The method of calculating the left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value further includes: Substitute the right ear hearing protector attenuation value as the hearing protector sound attenuation value into the calculation formula of the A-weighted noise sound attenuation statistical value to calculate the A-weighted noise sound attenuation statistical value of the right ear. The calculation formula of the A-weighted noise sound attenuation statistical value is: Where FAESA is the A-weighted noise attenuation statistic, n is the serial number of the industrial noise spectrum, k is the serial number of each frequency point in the 1 / 1OCT octave, Ak is the A-weighted attenuation value of each frequency point in the 1 / 1OCT octave, Ln,k 为 Spectral sound pressure level corresponding to the kth frequency point and the nth industrial noise spectrum in the 1 / 1OCT octave band ， Latten,k is the sound attenuation value of the hearing protector; Set the weight coefficient factor; Substitute the weight coefficient factor and the A-weighted noise attenuation statistical value of the right ear into the calculation formula of the personal sound attenuation value to obtain the personal sound attenuation value of the right ear. The calculation formula of the personal sound attenuation value is: Among them, PARx is the personal sound attenuation value, x is the weight coefficient factor, αx is the weight coefficient, FAESA is the A-weighted noise sound attenuation statistical value, is the comprehensive measurement uncertainty of the A-weighted noise attenuation statistical value.

6. The method for detecting the personal sound attenuation value of a hearing protector according to claim 5, characterized in that: The method of calculating the left ear personal sound attenuation value, the right ear personal sound attenuation value, and the binaural comprehensive personal sound attenuation value based on the left ear hearing protector sound attenuation value and the right ear hearing protector sound attenuation value further includes: The smaller value between the attenuation value of the left ear hearing protector and the attenuation value of the right ear hearing protector is used as the binaural integrated sound attenuation value; Substitute the binaural comprehensive sound attenuation value as the hearing protector sound attenuation value into the calculation formula of the A-weighted noise sound attenuation statistical value to calculate the binaural A-weighted noise sound attenuation statistical value. The calculation formula of the A-weighted noise sound attenuation statistical value is: Wherein, FAESA is the A-weighted noise attenuation statistic, n is the serial number of the industrial noise spectrum, k is the serial number of each frequency point in the 1 / 1OCT octave, Ak is the A-weighted attenuation value of each frequency point in the 1 / 1OCT octave, Ln,k is the spectral sound pressure level corresponding to the k-th frequency point in the 1 / 1OCT octave and the n-th industrial noise spectrum, and Latten,k is the sound attenuation value of the hearing protector; Set the weight coefficient factor; Substitute the weight coefficient factor and the A-weighted noise attenuation statistics of both ears into the calculation formula of the personal sound attenuation value to obtain the personal sound attenuation value of both ears. The calculation formula of the personal sound attenuation value is: Among them, PARx is the personal sound attenuation value, x is the weight coefficient factor, αx is the weight coefficient, FAESA is the A-weighted noise sound attenuation statistical value, is the comprehensive measurement uncertainty of the A-weighted noise attenuation statistical value.

7. The method for detecting the personal sound attenuation value of a hearing protector according to claim 1, characterized in that: The first test sound is a broadband white noise signal or a broadband pink noise signal, and the second test sound is a broadband white noise signal or a broadband pink noise signal.

8. The method for detecting the personal sound attenuation value of a hearing protector according to claim 1, characterized in that: The straight-line distance between the sound source and the physical center of the subject's head is less than or equal to a preset distance, which is 1 meter.

9. The method for detecting the personal sound attenuation value of a hearing protector according to claim 1, characterized in that: The microphone arranged outside the left ear is fixed at a fixed position outside the left ear through a fixing bracket, and the microphone arranged outside the right ear is fixed at a fixed position outside the right ear through a fixing bracket.

10. The method for detecting the personal sound attenuation value of a hearing protector according to claim 1, characterized in that: The microphone arranged in the ear canal of the left ear and the microphone arranged in the ear canal of the right ear are both connected through a flexible sound-transmitting wire and a fixed bracket.

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