Subjective measurement system and method for sound attenuation of hearing protector

Abstract

The invention discloses a subjective measurement system and method for sound attenuation of a hearing protector, relates to the technical field of measurement of sound attenuation of the hearing protector, and solves the problems that in the prior art, construction of a system needed for measurement of the sound attenuation of the hearing protector is expensive, and operation is complex and efficiency is low due to the fact that manual adjustment and recording are needed. The method comprises an electronic device, a transponder, a test signal source, a dual-channel power amplifier, a first audiometry loudspeaker and a second audiometry loudspeaker. The test signal source, the transponder, the dual-channel power amplifier and the two loudspeakers which are relatively low in price are selected to be matched with the electronic equipment with the data processing capacity, subjective measurement of the sound attenuation of the hearing protector can be achieved, and compared with a measurement system in the prior art, the system has the advantages of being low in cost and convenient to assemble, and the system is suitable for popularization and application. And automatic adjustment and recording of the test signal can be realized by using the electronic equipment, so that the measurement efficiency is greatly improved.

Description

Technical Field

[0001] This application relates to the technical field of measuring the sound attenuation of hearing protectors, and in particular to a subjective measurement system and method for the sound attenuation of hearing protectors. Background Art

[0002] A hearing protector refers to an instrument worn by an individual to prevent the unwanted effects of noise stimuli on hearing; (pure tone) hearing level refers to the difference between the pure tone sound pressure level generated by the earphone in a specified acoustic coupling cavity or artificial ear and the corresponding reference equivalent threshold sound pressure level at a specified frequency, for a specified type of earphone and specified usage method; the hearing threshold refers to the lowest sound pressure level at which the subject can correctly perceive 50% of the repeated tests under specified conditions; the sound attenuation amount refers to the difference between the hearing thresholds of the subject with and without wearing a hearing protector for a given test signal, expressed in decibels.

[0003] According to modern scientific research, long-term high-decibel noise will cause damage to the human ear and other diseases. Choosing a suitable hearing protector can effectively protect personnel in a noisy environment. The sound attenuation amount of a hearing protector is an important indicator to evaluate its protection effect, so a suitable and efficient method is needed to measure the sound attenuation of hearing protectors.

[0004] Part <GB / T 7584.1-2004 Acoustics - Hearing protectors - Part 1: Subjective method for the measurement of sound attenuation> (ISO 4869-1:1990, IDT) of this standard specifies a subjective measurement method for measuring the sound attenuation value of hearing protectors at the hearing threshold, and this sound attenuation value cannot be obtained under normal sound field test conditions.

[0005] Secondly, for hearing protectors whose sound attenuation is closely related to the sound pressure amplitude, when the sound pressure level exceeds the effective point of its relevant characteristics, the existing subjective methods for measuring sound attenuation often underestimate the sound attenuation value of the hearing protector. According to the standard requirements, the existing instrument equipment needs to use a pink noise signal source and a 1 / 3 OCT narrowband filter combination to generate more than two channels of non-coherent 1 / 3 OCT narrowband pink noise required for testing. After combination, the price is expensive, the wiring is complex, and it requires a large amount of working space. It is also difficult to implement the control of the amplitude and frequency of the test signal by a computer and the recording of data at the same time. In the prior art, it is necessary to completely rely on manual adjustment of the amplitude and frequency of the test signal and recording of data, resulting in very low measurement efficiency. Long-term measurement will also make the subjects who cooperate with the measurement anxious and uneasy. Summary of the Invention

[0006] The purpose of this application is to overcome the problems of complex operation and low efficiency caused by the expensive system construction required for measuring the sound attenuation amount of hearing protectors in the prior art and the need for manual adjustment and recording, and to provide a subjective measurement system and method for the sound attenuation of hearing protectors.

[0007] In a first aspect, a subjective measurement system for sound attenuation of a hearing protector is provided, including:

[0008] An electronic device for controlling the output of a test signal and recording the output amplitude corresponding to the current test frequency according to a response signal;

[0009] A transponder for sending a response signal to the electronic device;

[0010] A test signal source for outputting a two-channel test signal under the control of the electronic device;

[0011] A two-channel power amplifier for amplifying the test signal output by the test signal source;

[0012] A first audiometric loudspeaker and a second audiometric loudspeaker for converting the amplified test signal into a test sound signal. During the test, the first audiometric loudspeaker and the second audiometric loudspeaker are placed in a diffuse sound field, and the test sound signals emitted by the first audiometric loudspeaker and the second audiometric loudspeaker propagate towards the subject's head from different angles and at equal propagation distances.

[0013] In some possible implementation manners, a sound level meter for calibrating the diffuse sound field is further included. When calibrating the diffuse sound field, the sound level meter is fixed in the area where the subject's head is located in the diffuse sound field, and the diffuse sound field can be calibrated by using the sound level meter so that the diffuse sound field can meet the requirements for the test site in "4.2 Test Site" of "GB / T 7584.1-2004".

[0014] In some possible implementation manners, the two-channel audiometric signal includes a two-channel incoherent narrowband pink noise test signal. Using the two-channel incoherent narrowband pink noise test signal not only meets the 1 / 3 octave bandwidth requirement of GB / T3241, but also there is no fixed phase relationship between the frequency components of the signal, which can avoid standing waves or sound field interference phenomena caused by coherent signals and improve the stability of the measurement results.

[0015] In some possible implementation manners, the dynamic ranges of the test signal source and the two-channel power amplifier are both greater than 120 dB, and the signal-to-noise ratio of the two-channel power amplifier is greater than 120 dB, so that the test signal source and the two-channel power amplifier can meet the requirements in "GB / T 7584.1-2004".

[0016] In a second aspect, a subjective measurement method for sound attenuation of a hearing protector is provided, including the measurement system described in any one of the implementation manners in the first aspect above. The measurement method includes:

[0017] S100. Preset a test signal set including multiple different center frequencies;

[0018] S200. The subject enters the test position in the diffuse sound field without wearing a hearing protector and holds the transponder.

[0019] S300. Automatically select a test signal from the test signal set through the electronic device, and automatically control the selected test signal to start testing from the lowest output amplitude, and gradually increase the output amplitude of the test signal in a step-by-step manner.

[0020] S400. If the subject hears the test sound signal emitted by the speaker, press the transponder, and the electronic device records the output amplitude corresponding to the test signal of the current center frequency after receiving the response signal.

[0021] S500. Repeat steps S300 - S400 until all the test signals in the test signal set are tested.

[0022] S600. The subject wears a hearing protector and enters the test position in the diffuse sound field and holds the transponder, and repeat steps S300 - S500.

[0023] S700. Calculate the amplitude difference corresponding to the electronic device at different frequencies when the subject is not wearing a hearing protector and wearing a hearing protector as the first measurement result.

[0024] In some possible implementation manners, it further includes: replacing different subjects and repeating steps S200 - S700, calculating the average value of the corresponding sound attenuation values in the first measurement results of different subjects at the same frequency as the second measurement result, and measuring through different subjects and calculating the average sound attenuation values of different subjects at different frequencies as the final measurement result to obtain a more real measurement result.

[0025] In some possible implementation manners, it further includes: arranging the first audiometry speaker and the second audiometry speaker in the test sound field, fixing the microphone of the sound level meter at the midpoint of the line connecting the two ears after the subject enters the test position, the axis of the microphone coincides with the horizontal perpendicular bisector of the line connecting the two ears of the subject, and adjusting the output amplitude of the test signal of each center frequency so that the 1 / 3 OCT reading displayed on the sound level meter is 70 dB, and recording the current output adjustment position as the adjustment reference position corresponding to this frequency.

[0026] In some possible implementation manners, the center frequencies of the test signals in the test signal set include at least one of the following: 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz.

[0027] In some possible implementation manners, the spatial dimensions of the diffuse sound field meet the following requirements: length ≥ 2.5 m, width ≥ 2.5 m, height ≥ 2.2 m. After the subject enters the test position in the diffuse sound field, the head is located at the middle position of the test sound field, so that the test sound field can meet the requirements for the test site in "4.2 Test Site" of "GB / T 7584.1-2004", and can minimize the floor area of the test site as much as possible.

[0028] In some possible implementation manners, the diffuse sound field meets the following requirements:

[0029] The reverberation time of the test signal at each center frequency at the test position does not exceed 1.6 s;

[0030] The background noise of the test signal at each center frequency at the test position does not exceed the corresponding preset value.

[0031] The present application has the following beneficial effects:

[0032] 1. In the measurement system of the present application, by selecting a test signal source, a transponder, a two-channel power amplifier and two speakers with relatively low prices and an electronic device with data processing ability, the subjective measurement of the sound attenuation of the hearing protector can be realized. Compared with the measurement systems in the prior art, the present application has the advantages of low cost and convenient assembly, and the automatic adjustment and recording of the test signal can be realized by using the electronic device, greatly improving the measurement efficiency;

[0033] 2. In the measurement method of the present application, the subject only needs to hold the transponder and enter the test position in the diffuse sound field. The electronic device automatically selects the test signal from the pre-set test signal set and automatically realizes the step-by-step increase of the amplitude of the test signal. Without too much intervention from the staff, the selection, amplitude modulation of the test signal and the automatic recording of the amplitude corresponding to the current test signal frequency after the subject hears the sound can be realized. After the test signals in the test signal set are tested, the sound attenuation value measured by the current subject can be automatically calculated by the electronic device, thus effectively improving the measurement efficiency and effectively shortening the measurement duration of the subject. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings forming a part of the present application are used to provide a further understanding of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application.

[0035] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 is a schematic diagram of the subjective measurement system for the sound attenuation of a hearing protector in Embodiment 1 of the present application;

[0037] Figure 2 is a schematic diagram of the diffuse sound field of the subjective measurement system for the sound attenuation of a hearing protector in Embodiment 1 of the present application;

[0038] Figure 3 is a flowchart of the subjective measurement method for the sound attenuation of a hearing protector in Embodiment 2 of the present application.

[0039] Reference numerals:

[0040] 100, electronic device; 200, transponder; 300, test signal source; 400, dual-channel power amplifier; 500, first audiometric loudspeaker; 600, second audiometric loudspeaker; 700, diffuse sound field; 800, sound level meter; 900, audiometric room; 901, hearing protector; 902, subject. Detailed implementation manners

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0042] Embodiment 1

[0043] As Figure 1As shown in the figure, a subjective measurement system for the sound attenuation of a hearing protector according to Embodiment 1 of the present application includes an electronic device 100. Among them, the electronic device 100 can be an electronic device 100 with data processing capabilities such as a notebook computer or a desktop computer pre-installed with upper computer software. For the convenience of viewing the measurement results, the electronic device 100 can also have a display screen for displaying the measurement results. The electronic device 100 is used to control the output of the test signal and record the output amplitude corresponding to the current test frequency according to the response signal; the transponder 200 is communicatively connected to the electronic device 100. Among them, the communication connection between the transponder 200 and the electronic device 100 can be a wired connection or a wireless connection such as Bluetooth or a local area network. The transponder 200 is used to send a response signal to the electronic device 100 after the subject 902 presses the button on the transponder 200; the test signal source 300 is electrically connected to the electronic device 100, and the test signal source 300 is used to output a two-channel test signal under the control of the electronic device 100; the two-channel power amplifier 400 is electrically connected to the output end of the test signal source 300, and the two-channel power amplifier 400 is used to amplify the test signal output by the test signal source 300; the first audiometric speaker 500 and the second audiometric speaker 600 are respectively electrically connected to the two output channels of the two-channel power amplifier 400. The first audiometric speaker 500 and the second audiometric speaker 600 are used to convert the amplified test signal into a test sound signal and play it out in the direction of the subject 902's head. Among them, during the test, the first audiometric speaker 500 and the second audiometric speaker 600 are placed in the diffuse sound field 700, and the test sound signals emitted by the first audiometric speaker 500 and the second audiometric speaker 600 propagate from different angles to the subject 902's head and the propagation distances are equal.

[0044] As Figure 2As shown in the figure, in accordance with the requirements for the test site in the standard "GB / T 7584.1-2004 Acoustics - Hearing protectors - Part 1: Subjective method for the measurement of sound attenuation" (ISO 4869-1:1990, IDT) (hereinafter referred to as the standard "GB / T 7584.1-2004"), the audiometric room 900 is a diffuse sound field 700, so it is necessary to have sufficient volume. Generally, it is required that the internal space length × width × height of the audiometric room 900 is greater than or equal to 2.5m × 2.5m × 2.2m. In order to easily meet the requirements for the diffuse sound field 700, it is generally recommended that the seat of the subject 902 be in the middle position of the audiometric room 900. The first audiometric loudspeaker 500, the second audiometric loudspeaker 600 and the subject 902 form an isosceles triangle (the height of this isosceles triangle is 1m), and the axes of the two first audiometric loudspeakers 500 and the second audiometric loudspeaker 600 are both aligned with the midpoint of the line connecting the two ears of the subject 902. Considering that when the subject 902 is sitting on the chair, the height of the ears is about 1m, so it is more appropriate that the height of the front center points of the first audiometric loudspeaker 500 and the second audiometric loudspeaker 600 is basically set at about 1m.

[0045] Although the standard "GB / T 7584.1-2004" does not stipulate the requirements for the geometric dimensions of the audiometric room 900, in order to better meet the conditions of the diffuse sound field 700 and the comfort of the subject 902, the positions of the subject 902, the first audiometric loudspeaker 500 and the second audiometric loudspeaker 600, and the size of the audiometric room 900 are determined. Among them, the diffuse sound field 700 needs to meet the following conditions:

[0046] 1. When the subject 902 and their chair are not present, the deviation between the sound pressure levels measured at various positions 0.15m in front of, behind, left, right, above and below the reference point with an omnidirectional microphone and the sound pressure level at the reference point shall not exceed ±2.5dB for any test signal. The difference in sound pressure levels between the left and right end point positions shall not exceed 3dB, and the orientation of the microphone shall be kept consistent at each test position.

[0047] 2. At frequencies of 500Hz and above, a directional microphone with a forward - random incidence sensitivity index of 5dB is used. At the reference point, the difference between the maximum and minimum sound pressure levels obtained from two directions shall not exceed 5dB. For other directional microphones, the relationship between the forward - random incidence sensitivity index and the allowable sound deviation is shown in Table 1:.

[0048] Table 1: Allowable sound field deviations for different microphones

[0049]

[0050] In an optional embodiment, it further includes a sound level meter 800 for calibrating the diffuse sound field 700. During the process of calibrating the diffuse sound field 700, the sound level meter 800 is used to measure the sound pressure level of the diffuse sound field 700. It should be noted that the above test of the diffuse sound field 700 needs to be carried out in enough directions, which depends on the type of microphone and the placement characteristics of the loudspeakers. At least two planes that can obtain the maximum and minimum sound pressure levels should be included. To obtain the desired diffuse sound field 700, there should be no less than two loudspeakers, and they are required to be fed with incoherent electrical signals to reduce the standing wave effect.

[0051] In accordance with the requirements of the standard "GB / T 7584.1-2004", at the test position (with the subject 902 not present). The reverberation time of each test frequency does not exceed 1.6 s. In the audiometric room 900, when the subject 902 is not present, the background noise at the test position does not exceed the value given in Table 2. The background noise should be determined by measuring the sound pressure level, where the background noise includes the ambient noise in the test room and the background noise of the test instrument without a test signal.

[0052] Table 2: Maximum allowable background noise sound pressure level

[0053]

[0054] In the above table, *) represents optional.

[0055] Exemplarily, when the center frequency of the lowest test frequency band is 125 Hz, the background noise requirement should be low enough that it meets the standard down to 63 Hz; when the center frequency of the lowest test frequency band is 63 Hz, the background noise requirement should be low enough that it meets the standard down to 31.5 Hz.

[0056] Taking the computer mainframe as the electronic device 100 as an example, the operating system of the computer mainframe selects Win10 or Win11, and a dedicated upper computer software is pre-installed, which is used to control the output of the test signal in the test signal source 300 and record the measurement results according to the response signal sent by the transponder 200 to generate a test report.

[0057] For the test signal source 300, the test signal source 300 outputs the required dual-channel incoherent narrowband pink noise test signal under the control of the upper computer software pre-installed on the computer mainframe. The characteristics of the test signal meet the 1 / 3 octave bandwidth requirements of GB / T3241. The test should be carried out at the following center frequencies: 63 Hz (selectable as needed), 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz. The amplitude of the test signal is controlled step by step using the signal source attenuator. Under the control of the upper computer software, the step of the signal source attenuator is 2.5 dB or less than 2.5 dB, and the dynamic range of the signal source is greater than 120 dB.

[0058] For the dual-channel power amplifier 400, the signal-to-noise ratio of the dual-channel power amplifier 400 is greater than 120 dB. The test signal source 300, the dual-channel power amplifier 400, the first audiometric loudspeaker 500, and the second audiometric loudspeaker 600 are combined to output the required test sound signal, meeting the requirements of Table 3 (the data in the table refers to the description in the standard "GB / T 7584.1-2004"). Since in Table 3, the sound pressure level of the test signal above 2000 Hz is -20 dB to 90 dB, and its dynamic range is at least 110 dB, in order to ensure the accuracy of the test results, it is required that the dynamic ranges of the signal source and the power amplifier in this system are both greater than 120 dB.

[0059] Table 3: Minimum and maximum test signal sound pressure levels

[0060]

[0061] In the above Table 3, *) represents optional, and **) represents the distortion limits listed in the text, which apply at least to sound pressure levels above 70 dB.

[0062] When outputting the test signals of each test frequency band and each test sound pressure level listed in Table 3, there will be no audible pops and rattles. For the complete set of test equipment including the first audiometric loudspeaker 500 and the second audiometric loudspeaker 600, the error between the readings measured at any two positions of the signal source attenuator does not exceed 2 dB within the full range of the signal source attenuator; and does not exceed 1 dB within any 80 dB range.

[0063] In this embodiment, by selecting a relatively low-cost test signal source 300, a transponder 200, a dual-channel power amplifier 400, and two loudspeakers, and matching with a computer host with data processing capabilities, the subjective measurement of the sound attenuation of the hearing protector can be realized. Compared with the measurement system in the prior art, the measurement system of this embodiment has the advantages of low cost and convenient assembly, and can realize the automatic adjustment and recording of the test signal by using a computer host pre-installed with upper computer software, greatly improving the measurement efficiency, and at the same time meeting the requirements of the subjective method for sound attenuation measurement in the standard "GB / T 7584.1-2004".

[0064] Embodiment 2

[0065] As Figure 3 shown, for a subjective measurement method of the sound attenuation of a hearing protector involved in Embodiment 2 of the present application, taking a computer host as the electronic device 100 as an example, the automatic measurement method includes:

[0066] First, it is necessary to calibrate the diffuse sound field 700. The following is the calibration process of the diffuse sound field 700:

[0067] Arrange the first audiometric speaker 500 and the second audiometric speaker 600 in the test sound field. Fix the microphone of the sound level meter 800 at the midpoint of the line connecting the two ears after the subject 902 enters the test position. The axis of the microphone coincides with the horizontal perpendicular bisector of the line connecting the two ears of the subject 902. Herein, the horizontal perpendicular bisector refers to a straight line that passes through the midpoint of the line connecting the two ears of the subject 902, is perpendicular to the line connecting the two ears of the subject 902, and is horizontal. Adjust the output amplitude of the test signals at each center frequency so that the 1 / 3 OCT reading displayed on the sound level meter 800 is 70 dB. Record the current output adjustment position as the adjustment reference position corresponding to this frequency. Among them, according to the standard "GB / T 7584.1-2004", when calibrating the sound field, the sound pressure at the test point needs to be 70 dB. At the same time, since the maximum output range of the test signal is -20 dB to 90 dB, it is reasonable to use 70 dB as the reference point for calibrating the diffuse sound field amplitude. In addition, since the output signal is a two-channel incoherent narrowband pink noise test signal, in order to reduce the noise influence of other non-test signals and ensure the accuracy of the sound field calibration, it is reasonable to select the reading analyzed by 1 / 3 OCT on the sound level meter. In addition, when calibrating the diffuse sound field, the position of the sound level meter remains unchanged, that is, the sound level meter is always fixed at the head position of the subject (specifically, the axis of the microphone of the sound level meter coincides with the horizontal perpendicular bisector of the line connecting the two ears of the subject 902, and in the diffuse sound field calibration, there is no subject in the diffuse sound field). The recorded position is the position where the output amplitude of the signal is adjusted, which can be understood as the position of a potentiometer for adjusting the output amplitude of the signal. Secondly, when calibrating the sound field, since the sensitivity frequency responses of the first audiometric speaker 500 and the second audiometric speaker 600 are not completely horizontal, when changing the center frequency of the test signal, it is necessary to adjust the output amplitude of the test signal so that when changing the test signal frequency, the corresponding 1 / 3 OCT analysis reading on the sound level meter remains at 70 dB.

[0068] S100. Preset a test signal set including multiple different center frequencies. Among them, the center frequencies of the test signals in the test signal set include at least one of the following: 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz;

[0069] S200. The subject 902 enters the test position of the diffuse sound field 700 without wearing hearing protectors and holds the transponder 200. When the subject 902 presses the button on the transponder 200, the computer host can receive the response signal, and thus automatically records the measurement results;

[0070] S300. Automatically select a test signal from the test signal set by the computer host. Among them, in order to test the test signals in the test signal set orderly and without omission, the selection order of the test signals in the test signal set can be preset. For example, start selecting frequencies incrementally from 1000 Hz, when reaching the highest frequency, then start selecting frequencies incrementally from the lowest frequency until 1000 Hz ends, and set the residence time for each amplitude step to leave enough reaction time for the subject 902 to press the transponder 200. For example, set the residence time after each amplitude step to 8 s, 10 s, 11 s, etc., and automatically control the selected test signal by the computer host to start testing from the lowest output amplitude, and gradually increase the output amplitude of the test signal in a step-by-step manner, with the amplitude of each step not exceeding 2.5 dB;

[0071] S400. If the subject 902 hears the test sound signal emitted by the speaker, press the transponder 200, and the computer host records the output amplitude corresponding to the test signal of the current center frequency after receiving the response signal;

[0072] S500. Repeat steps S300 - S400, then conduct the test of the next test signal in the test signal set until all the test signals 300 in the test signal set are tested. The computer host can automatically complete the first output amplitude when the subject 902 hears the test sound signal corresponding to the recorded different center frequencies. For example, when the center frequency is 1000 Hz, the recorded output amplitude is 30 dB;

[0073] S600. The subject 902 wears a hearing protector and enters the test position in the reverberation chamber 700 and holds the transponder 200, and repeat steps S300 - S500. Specifically:

[0074] S601. Automatically select a test signal from the test signal set by the computer host. Among them, in order to test the test signals in the test signal set orderly and without omission, the selection order of the test signals in the test signal set can be preset. For example, start selecting frequencies incrementally from 1000 Hz, when reaching the highest frequency, then start selecting frequencies incrementally from the lowest frequency until 1000 Hz ends, and set the residence time for each amplitude step to leave enough reaction time for the subject 902 to press the transponder 200. For example, set the residence time after each amplitude step to 8 s, 10 s, 11 s, etc., and automatically control the selected test signal by the computer host to start testing from the lowest output amplitude, and gradually increase the output amplitude of the test signal in a step-by-step manner, with the amplitude of each step not exceeding 2.5 dB;

[0075] S602. If the subject 902 hears the test sound signal emitted by the speaker, press the transponder 200, and the computer host records the output amplitude corresponding to the test signal of the current center frequency after receiving the response signal;

[0076] S603. Repeat steps S601 - S602, then proceed with the test of the next test signal in the test signal set until all the test signals 300 in the test signal set are tested. The computer host can automatically complete the second output amplitude when the corresponding recorded subject 902 hears the test sound signal at different center frequencies. For example, when the center frequency is 1000 Hz, the recorded output amplitude is 65 dB.

[0077] S700. Calculate the amplitude difference corresponding to different frequencies of the computer host with the subject 902 not wearing the hearing protector and wearing the hearing protector as the first measurement result. Taking the center frequency of 1000 Hz as an example, in the above steps, the first output amplitude recorded by the computer host at the 1000 Hz center frequency with the subject 902 not wearing the hearing protector is 30 dB, while the first output amplitude recorded by the computer host at the 1000 Hz center frequency with the subject 902 wearing the hearing protector is 65 dB. Then the first measurement result of the subject 902 at the 1000 Hz center frequency is 65 dB - 30 dB = 35 dB.

[0078] To eliminate the inaccuracy of the measurement results caused by the hearing differences of different subjects 902, multiple different subjects 902 are required to test the same hearing protector and calculate the average value as the final test result. That is, repeat steps S200 - S700 with different subjects 902, and calculate the average value of the corresponding sound attenuation values in the first measurement results of different subjects 902 at the same frequency as the second measurement result. For example, through three subjects 902 for measurement, the three subjects 902 are: Subject A, Subject B, and Subject C. Among them, at the 1000 Hz center frequency, the first measurement result recorded by Subject A on the computer host is 35 dB, the first measurement result recorded by Subject B on the computer host is 37.5 dB, and the first measurement result recorded by Subject C on the computer host is 42.5 dB. Then the final second measurement result corresponding to 1000 hz is: (35 dB + 37.5 dB + 42.5 dB) / 3 ≈ 38.33 dB. Of course, more subjects 902 can also be tested, and after removing the maximum and minimum values and then calculating the average value, it can reduce the interference of the hearing factors and subjective factors of different subjects 902, thereby improving the authenticity and accuracy of the measurement results.

[0079] In another implementation, the output frequency and amplitude of the test signal can also be manually adjusted by the operator on the computer host, and the remaining test process is the same as the above automatic test process. To avoid redundancy, it will not be elaborated here.

[0080] It should be noted that for other specific implementation manners of the subjective measurement method of the hearing protector sound attenuation in this embodiment, reference may be made to the specific implementation manners of the above-mentioned subjective measurement system of the hearing protector sound attenuation. To avoid redundancy, it will not be elaborated here.

[0081] In the automatic measurement method of this embodiment, the subject 902 only needs to hold the transponder 200 and enter the test position of the diffuse sound field 700. The electronic device 100 automatically selects a test signal from a pre-set test signal set and automatically realizes a step-by-step increase in the amplitude of the test signal. Without too much intervention from the staff, the selection and amplitude modulation of the test signal can be achieved, and when the subject 902 hears the sound, pressing the transponder 200 can automatically record the amplitude corresponding to the current test signal frequency. After the test signals in the test signal set are all tested, the electronic device 100 can automatically calculate the sound attenuation value measured by the current subject 902, thereby effectively improving the measurement efficiency and effectively shortening the measurement duration of the subject 902.

[0082] The above is only the preferred specific implementation manner of the present application; however, the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application, according to the technical solution of the present application and its improved concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present application.

Claims

1. A subjective measurement system for the sound attenuation of a hearing protector, characterized in that, Comprising: An electronic device, configured to control the output of a test signal and record the output amplitude corresponding to the current test frequency according to a response signal; A transponder, configured to send a response signal to the electronic device; A test signal source, configured to output a dual-channel test signal under the control of the electronic device; A dual-channel power amplifier, configured to amplify the test signal output by the test signal source; A first audiometric loudspeaker and a second audiometric loudspeaker, configured to convert the amplified test signal into a test sound signal. During the test, the first audiometric loudspeaker and the second audiometric loudspeaker are placed in a diffuse sound field, and the test sound signals emitted by the first audiometric loudspeaker and the second audiometric loudspeaker propagate towards the subject's head from different angles and at equal propagation distances.

2. The subjective measurement system for hearing protector sound attenuation according to claim 1, wherein It further includes a sound level meter for calibrating the diffuse sound field. When calibrating the diffuse sound field, the sound level meter is fixed in the area where the subject's head is located in the diffuse sound field.

3. The subjective measurement system for the sound attenuation of a hearing protector according to claim 1, characterized in that The dual-channel audiometric signal includes a dual-channel incoherent narrowband pink noise test signal.

4. The subjective measurement system for the sound attenuation of a hearing protector according to claim 1, characterized in that, The dynamic ranges of the test signal source and the dual-channel power amplifier are both greater than 120 dB, and the signal-to-noise ratio of the dual-channel power amplifier is greater than 120 dB.

5. A subjective measurement method for the sound attenuation of a hearing protector, characterized in that, Comprising the measurement system according to any one of claims 1-3, the measurement method comprising: S100. Preset a test signal set including multiple different center frequencies in advance; S200. The subject enters the test position in the diffuse sound field without wearing hearing protectors and holds the transponder; S300. Automatically select a test signal from the test signal set by the electronic device, and automatically control the selected test signal to start testing from the lowest output amplitude, and gradually increase the output amplitude of the test signal in a step-by-step manner; S400. If the subject hears the test sound signal emitted by the loudspeaker, press the transponder, and the electronic device records the output amplitude corresponding to the test signal of the current center frequency after receiving the response signal; S500. Repeat steps S300-S400 until all the test signals in the test signal set are tested; S600. The subject wears hearing protectors and enters the test position in the diffuse sound field and holds the transponder, and repeat steps S300-S500; S700. Calculate the amplitude difference corresponding to different frequencies of the electronic device when the subject does not wear hearing protectors and wears hearing protectors as the first measurement result.

6. The subjective measurement method for the sound attenuation of a hearing protector according to claim 5, characterized in that, It further includes: Replace different subjects and repeat steps S200-S700, and calculate the average value of the corresponding sound attenuation values in the first measurement results of different subjects at the same frequency as the second measurement result.

7. The subjective measurement method for the sound attenuation of a hearing protector according to claim 5 or 6, characterized in that, It further includes: Arrange the first audiometric loudspeaker and the second audiometric loudspeaker in the test sound field, fix the microphone of the sound level meter at the midpoint of the line connecting the two ears after the subject enters the test position, the axis of the microphone coincides with the horizontal perpendicular bisector of the line connecting the subject's two ears, adjust the output amplitude of the test signal of each center frequency so that the 1 / 3 OCT reading displayed on the sound level meter is 70 dB, and record the current output adjustment position as the adjustment reference position corresponding to this frequency.

8. The subjective measurement method for the sound attenuation of a hearing protector according to claim 5 or 6, characterized in that The center frequencies of the test signals in the test signal set include at least one of the following: 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz.

9. The subjective measurement method for the sound attenuation of a hearing protector according to claim 5, characterized in that, The spatial dimensions of the diffuse sound field meet the following requirements: length ≥ 2.5 m, width ≥ 2.5 m, height ≥ 2.2 m. After the subject enters the test position in the diffuse sound field, the head is located at the middle position of the test sound field.

10. The subjective measurement method for the sound attenuation of a hearing protector according to claim 5, characterized in that, The diffuse sound field meets the following requirements: The reverberation time of the test signal at each center frequency at the test position does not exceed 1.6 s; The background noise of the test signal at each center frequency at the test position does not exceed the corresponding preset value.

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