CN115389631A - Method for measuring acoustic performance of mute chamber - Google Patents

Method for measuring acoustic performance of mute chamber Download PDF

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Publication number
CN115389631A
CN115389631A CN202211009620.2A CN202211009620A CN115389631A CN 115389631 A CN115389631 A CN 115389631A CN 202211009620 A CN202211009620 A CN 202211009620A CN 115389631 A CN115389631 A CN 115389631A
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mute
measuring
cabin
sound
pressure level
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戴璐
赵雨生
卢明辉
谢海圣
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Suzhou Acoustic Industrial Technology Research Institute Co ltd
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Suzhou Acoustic Industrial Technology Research Institute Co ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/04—Analysing solids
    • G01N29/11—Analysing solids by measuring attenuation of acoustic waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/01—Indexing codes associated with the measuring variable
    • G01N2291/015—Attenuation, scattering
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/023—Solids

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  • Acoustics & Sound (AREA)
  • Health & Medical Sciences (AREA)
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Abstract

The invention relates to a method for measuring the acoustic performance of a mute cabin, which is characterized in that a room in which the mute cabin is arranged and the interior of the mute cabin are isolated into two independent acoustic environments by utilizing a cabin body in a closed state, two nondirectional sound sources excited by a sound field in the room, six external test points and three external test point test points in the mute cabin are used as a sounding room for sound insulation test, and the mute cabin is used as a sound receiving room. The mute cabin is positioned in a reverberation sound field as much as possible, the accuracy of measured data is improved, and a basis is provided for mute cabins with different acoustic performances designed by mute cabin manufacturers.

Description

Method for measuring acoustic performance of mute chamber
Technical Field
The invention relates to a method for measuring acoustic performance of a mute chamber.
Background
The acoustic environment in the mute cabin directly influences the comfort of the personnel in the mute cabin, and is a key factor for ensuring and even improving the market competitiveness of the mute cabin industry. The acoustic environment in the quiet compartment is strongly related to the sound insulation properties of the panel walls, the sealing properties and the noise level of the ventilation system. The acoustic performance of the mute cabin is tested by selecting a proper measuring method, so that effective data support can be provided for the sound insulation design, the sealing treatment and the ventilation system design of the mute cabin. The existing laboratory sound insulation method only aims at the wallboard sample of an independent cabin body, and can not measure the whole sound insulation performance of the cabin body and the problem that the sound insulation interval performance measurement method can not completely represent the acoustic performance of the mute cabin, so the content of the invention aims to solve the problems.
Disclosure of Invention
The invention aims to provide a method for measuring the acoustic performance of a mute cabin, which solves the problem of acoustic performance test of the mute cabin.
In order to achieve the purpose, the invention adopts the technical scheme that:
the invention provides a method for measuring the acoustic performance of a mute cabin, which comprises the following steps:
s1: the closed mute cabin is asymmetrically placed on the ground of the measuring room and is not parallel to any wall surface in the measuring room,
s2: the effective sounding element in the mute cabin is closed and the ventilation system in the mute cabin is opened at the same time,
s3: uniformly arranging two speaker points on the periphery in the mute cabin, wherein the distance between the speaker points is at least 3.0m, and the distance between the mute cabin and the speaker points is not less than 2.0m;
s4: six external measuring points are arranged on the periphery of the loudspeaking point, the height of each external measuring point from the ground is more than 1.2m, and the distance between each external measuring point and any surface of a measuring room and a mute cabin is not less than 1.0m;
s5: three inner measuring point positions are arranged in the mute cabin, the three inner measuring point positions are distributed on a spherical surface with the radius of 0.3m and the center of the spherical surface at the auditory position of an operator, and the three measuring point positions refer to the positions of the nose and the ears of the operator; the height between the positions of all the internal measuring points and the ground is more than 1.2m;
s6; measuring the sound pressure level of background noise in the mute cabin, placing a sound level meter at the position of an inner measuring point, wherein the distance between the sound level meter and the ground of the mute cabin is more than 1.2m, closing a cabin door of the mute cabin, measuring the background noise at each position twice, and storing data;
s7: measuring the sound pressure level in a room, adjusting the height of a loudspeaking point to enable the height of the loudspeaking point to be larger than 1.5m from the ground of the room, placing a sound level meter on an external measuring point, starting a loudspeaker, measuring the sound pressure level of the loudspeaker in the room, measuring once at each position, and storing data;
s8: measuring the sound pressure level in the mute cabin, placing a sound level meter at the position of the inner measuring point, wherein the distance between the sound level meter and the ground of the mute cabin is more than 1.2m, starting a loudspeaker, closing a cabin door of the mute cabin, measuring the sound pressure level in the mute cabin, measuring the sound pressure level at each position twice, and storing data;
s9: measuring the noise sound pressure level of the ventilation equipment, adjusting the height of a loudspeaking point to enable the height of the loudspeaking point to be larger than 1.2m from the ground of a room, placing a sound level meter on an inner measuring point, opening the ventilation equipment, sequentially opening all gears, closing a door of a mute cabin, measuring the noise sound pressure level of the ventilation equipment, measuring the noise sound pressure level at each position twice, and storing data;
s10: detecting sound leakage of the mute cabin, and detecting sound leakage of the side seam of the mute cabin; and after the detection is finished, deriving an acoustic image.
S11: and performing data calculation, and then grading, wherein the grading comprises the grading of the sound insulation performance evaluation of the mute cabin and the grading of the noise size evaluation of the ventilation system of the mute cabin.
Preferably, all movable parts of the mute chamber should be operated at least 10 times before the measurement.
Preferably, the minimum distance between the loudspeaker and the nearest sound level meter position is not less than 0.3V 1/3 Where V is the volume of the room.
Preferably, the distance between the positions of the outsourcing points is not less than lambda/2, and lambda is the wavelength of the center frequency of the lowest octave band in the test frequency range.
Preferably, the difference between the sound pressure level of the background noise inside the mute chamber in S6 and the sound pressure level inside the mute chamber of the on speaker in S8 is 10dB to 15dB, and the data is corrected.
Further, the modified formula is L p ＝10log 10 (10 Lsb/10 -10 Lb/10 ) Wherein L is p Is a modified sound pressure level of the loudspeaker, of which 10 Lsb For silencing the sound pressure level in the chamber when the loudspeaker is switched on, L b Is the background noise sound pressure level inside the mute compartment.
Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:
the invention relates to a method for measuring the acoustic performance of a mute cabin, which initiatively provides a method for measuring the sound insulation performance of the mute cabin, a method for measuring a ventilation system and a method for detecting the sound leakage of a cabin body, and is suitable for a laboratory of the mute cabin and a field measurement.
Drawings
Some specific embodiments of the invention will be described in detail hereinafter, by way of illustration and not limitation, with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:
FIG. 1 is a schematic diagram of a station placement layout in a quiet cabin near a room wall;
FIG. 2 is a schematic diagram of a layout principle of measuring points placed on a wall of a room without a mute chamber;
FIG. 3 is a sound insulation performance evaluation grading of a mute cabin;
fig. 4 is a ventilation device noise level rating scale for a quiet compartment.
Wherein the reference numerals are as follows:
1. a mute cabin;
2. a room wall;
3. a loudspeaking point; 4. measuring points outside; 5. and (6) measuring the inner measuring point.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The present example relates to a method for measuring the acoustic performance of a mute chamber, which is an enclosure specially designed to protect people from noise.
The invention comprises the following steps:
s1: the mute chamber 1 is asymmetrically placed on the floor of the measurement room and is not parallel to any wall surface in the measurement room, because the parallel arrangement may generate resonance or the like to generate extra noise, and may or may not be close to the room wall 2. As shown in fig. 1 and 2, the mute chambers are placed at different positions.
S2: closing the effective sounding elements in the mute cabin 1 and simultaneously opening ventilation systems in the mute cabin, such as an exhaust fan and the like;
s3: two loudspeaking points are uniformly arranged on the periphery in the mute cabin 1, the distance between the loudspeaking points is at least 3.0m, and the distance between the mute cabin 1 and the loudspeaking point 3 is not less than 2.0m; avoiding proximity to the surfaces and corners of the measurement room; one loudspeaker can be used for moving between the selected positions to generate sound in sequence to form two loudspeaker points; it is also possible to operate two mutually independent loudspeakers simultaneously, each sounding separately.
S4: six external measuring points 4 are arranged on the periphery of the loudspeaking point 3 and are uniformly distributed around the mute cabin 1, the height of each external measuring point 4 from the ground is more than 1.2m, and the distance between each external measuring point 4 and any surface of a measuring room and the mute cabin 1 is not less than 1.0m; the minimum distance between the loudspeaker 3 and the outer measuring point 4 should be not less than 0.3V 1/3 (unit: m), where V is the volume of the room (unit: m) 3 ) (ii) a The spacing between the outer points 4 is not less than λ/2, λ being the wavelength of the center frequency of the lowest octave band in the test frequency range, and λ being typically 3.4m.
S5: three inner side points 5 are arranged in the mute cabin 1, the positions of the three inner side points 5 are distributed on a circular surface with the radius of 0.3, the center of the circular surface is positioned on a spherical surface of the auditory position of an operator, and the positions of the three measuring points refer to the positions of the nose and the ears of the operator; the height between the positions of all the inner side points 5 and the ground is more than 1.2m;
the number of speakers (sound source positions) should be greater than or equal to the maximum deviation DP' of the octave between any two sound source positions (e.g., deviation =2 for 100Hz sound, with 74dB sound pressure level at speaker position 1 and 76dB sound pressure level at speaker position 2), and not less than two, with the distance between the positions being set so that the sound field components in the room are diffused (i.e., the sound pressure levels in the room are not greatly different).
The number of the external measuring points is set so as to fully collect sound pressure level data of an external sound field, and the six positions are set so as to enable the positions of the microphones to be in a diffusion sound field;
the number of the inner measuring points is determined according to the number of one mouth and two ears of the human body, and the three positions are set according to the height of the sitting posture of the human body and the positions of the mouth and the two ears.
S6; measuring background noise in the mute cabin, namely placing a sound level meter at the position of an inner measuring point 5, wherein the distance between the sound level meter and the ground of the mute cabin is more than 1.2m, measuring the background noise of the mute cabin after closing a door of the mute cabin, measuring the background noise at each position twice, and storing data;
s7: measuring the sound pressure level in a room, adjusting the height of a loudspeaking point to enable the height of the loudspeaking point to be larger than 1.5m from the ground of the room, placing a sound level meter at the position of an external measuring point 4, starting a loudspeaker, measuring the sound pressure level of the loudspeaker in the room once at each position, and storing data;
s8: measuring the sound pressure level in the mute cabin, placing a sound level meter at the position of an inner measuring point 5, wherein the distance between the sound level meter and the ground of the mute cabin is more than 1.2m, starting a loudspeaker, closing a cabin door of the mute cabin, measuring the sound pressure level in the mute cabin, measuring the sound pressure level at each position twice, and storing data;
s9: measuring the noise of the ventilation equipment, namely placing a sound level meter on the inner measuring point 5, wherein the distance between the sound level meter and the ground of the mute cabin is more than 1.2m, opening the ventilation equipment, sequentially opening all gears, closing the cabin door of the mute cabin, measuring the noise sound pressure level of the ventilation equipment, measuring the noise sound pressure level twice at each position, and storing data;
s10: detecting sound leakage of the mute cabin, namely detecting the sound leakage of the side seam at the bottom of the mute cabin by using vector sound brush equipment; and after the detection is finished, deriving an acoustic image. The sonogram is intended to show the sealing performance of the quiet compartment.
S11: and (4) performing statistical calculation on all the recorded data, and then grading, wherein the grading comprises the sound insulation performance evaluation grading of the mute cabin and the noise size evaluation grading of a ventilation system of the mute cabin.
In S7, the sound pressure level of the background noise inside the mute compartment is at least 10dB, preferably 15dB, below the sound pressure level induced by the noise source (i.e. the loudspeaker in this example) turned on inside the mute compartment in each frequency band.
If the difference is between (10 dB to 15 dB), the correction for each band sound pressure level is calculated as follows (the difference is greater than 15dB without correction): the correction formula is as follows:
Figure BDA0003809987900000061
L p -the modified silence chamber sound pressure level;
L sb -turning on the sound pressure level of the loudspeaker being a static pressure cabin;
L b -background noise sound pressure level of static pressure cabin. The above units are all dB;
the average sound pressure level in the room or mute compartment is calculated as follows:
Figure BDA0003809987900000071
Figure BDA0003809987900000072
-average sound pressure level in a room or mute room;
L′ p -measuring the sound pressure level at each point of the room or silence chamber; the above units are all dB;
n-number of measurements.
Sound pressure sound insulation value D of mute cabin p Calculated as follows:
D p ＝(L p ) room -(L p ) cabin
dp-sound pressure insulation value, unit: dB;
(L p ) room -average sound pressure level of each frequency band in the room;
(L p ) cabin -average sound pressure level of each frequency band within the mute chamber.
Equivalent continuous a sound level L of a ventilation device Aeq，T Calculated as follows:
Figure BDA0003809987900000073
L Aeq，T -the equivalent continuous a sound level of the ventilation device;
L PA′ -sound pressure level of the selected frequency in 1/3 octave; the above units are dB (A);
n is the number of selected frequencies in the 1/3 octave frequency.
The sound insulation performance of the mute cabin is evaluated and graded, the evaluation is preferably graded into 5 grades, and the grading basis is the calculated D p The numerical value of (2), the range of the individual evaluation amount of each grade is shown in FIG. 3.
Then, the noise of the ventilation equipment of the mute cabin is evaluated and graded, the evaluation is preferably divided into 3 grades, and the grading basis is the calculated L Aeq，T The numerical value of (2), the range of the individual evaluation amount of each grade is shown in FIG. 4.
In summary, the patent initiatively provides a sound insulation performance measurement method of a mute cabin, a ventilation system measurement and a cabin body sound leakage detection, wherein a room in which the mute cabin is placed and the interior of the mute cabin are isolated into two independent acoustic environments by utilizing the cabin body in a closed state, the room is used as a sound producing room for sound insulation test, the mute cabin is used as a sound receiving room, the whole mute cabin is used as a test piece, the requirement on the placement position of the mute cabin is given, the mute cabin is positioned in a reverberation sound field as much as possible, and the accuracy of measurement data is improved. And through experimental tests and experience summarization of different mute cabins, the evaluation and classification of the sound insulation performance of the mute cabin and the evaluation and classification of the noise of a ventilation system of the mute cabin are initiatively provided, and a basis is provided for mute cabins with different acoustic performances designed by mute cabin manufacturers. The method is suitable for the whole sound insulation quantity of the cabin body, is suitable for different occasions, solves the problem that the laboratory sound insulation method can only test a single component, and has the advantages of easy satisfaction of test equipment and simple and understandable operation steps.
The above-mentioned embodiments are provided only for illustrating the technical idea and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the content of the present invention and to implement the present invention, and not to limit the protection scope of the present invention by this, and all equivalent changes or modifications made according to the spirit of the present invention should be covered in the protection scope of the present invention.

Claims (6)

1. A method for measuring acoustic performance of a mute chamber, comprising: it comprises the following steps:
s1: the mute cabin is asymmetrically placed on the ground of the measuring room and is not parallel to any wall surface in the measuring room,
s2: the active sound producing element in the mute cabin is closed and the ventilation system in the mute cabin is opened at the same time,
s3: uniformly arranging two speaker points on the periphery in the mute cabin, wherein the distance between the speaker points is at least 3.0m, and the distance between the mute cabin and the speaker points is not less than 2.0m;
s4: six external measuring points are arranged on the periphery of the loudspeaking point, the height of each external measuring point from the ground is more than 1.2m, and the distance between each external measuring point and any surface of a measuring room and a mute cabin is not less than 1.0m;
s5: three inner measuring point positions are arranged in the mute cabin, the three inner measuring point positions are distributed on a circular surface with the radius of 0.3m, and the three inner measuring point positions refer to the positions of the nose and the ears of an operator; the height of the position of the inner measuring point from the ground is more than 1.2m;
s6, measuring the sound pressure level of the background noise in the mute cabin, placing a sound level meter at the position of an inner measuring point, wherein the distance between the sound level meter and the ground of the mute cabin is more than 1.2m, closing the cabin door of the mute cabin, measuring the sound pressure level of the background noise twice at each position, and storing data;
s7: measuring the sound pressure level in a room, adjusting the height of a loudspeaking point to enable the height of the loudspeaking point to be larger than 1.5m from the ground of the room, placing a sound level meter on an external measuring point, starting a loudspeaker, measuring the sound pressure level of the loudspeaker in the room, measuring once at each position, and storing data;
s8: measuring the sound pressure level in the mute cabin, placing a sound level meter on an inner measuring point, wherein the distance between the sound level meter and the ground of the mute cabin is more than 1.2m, starting a loudspeaker, closing a cabin door of the mute cabin, measuring the sound pressure level in the mute cabin, measuring the sound pressure level twice at each position, and storing data;
s9: measuring the noise sound pressure level of the ventilation equipment, adjusting the height of a loudspeaking point to enable the height of the loudspeaking point to be larger than 1.2m from the ground of a room, placing a sound level meter on an inner measuring point, opening the ventilation equipment, sequentially opening all gears, closing a door of a mute cabin, measuring the noise sound pressure level of the ventilation equipment, measuring the noise sound pressure level at each position twice, and storing data;
s10: detecting sound leakage of the mute cabin, and detecting sound leakage of a side seam at the bottom of the mute cabin; after detection is finished, deriving an acoustic image;
s11: and calculating data, and then grading, wherein the grading comprises the evaluation grading of the sound insulation performance of the mute cabin and the evaluation grading of the noise size of a ventilation system of the mute cabin.
2. A method as claimed in claim 1, wherein the method comprises the steps of: all movable parts of the mute chamber should be operated at least 10 times before the measurement.
3. The method of measuring acoustical performance of a mute chamber as set forth in claim 1, wherein: the minimum distance between the loudspeaker and the nearest sound level meter position is not less than 0.3V 1/3 Where V is the volume of the room.
4. A method as claimed in claim 1, wherein the method comprises the steps of: the position spacing of the external measuring points is not less than lambda/2, and lambda is the wavelength of the center frequency of the lowest octave band in the measuring frequency range.
5. The method of measuring acoustical performance of a mute chamber as set forth in claim 1, wherein: and correcting the data of which the difference value between the sound pressure level of the background noise in the mute cabin in the S6 and the sound pressure level in the mute cabin of the on loudspeaker in the S8 is 10 dB-15 dB.
6. The method of claim 1 for measuring acoustical properties of a mute compartment,the method is characterized in that: the modified formula is L p =10log 10 （10 Lsb/10 -10 Lb/10 ) Wherein L is p Is a modified sound pressure level of the loudspeaker, of which 10 Lsb For silencing the sound pressure level in the chamber when the loudspeaker is switched on, L b Is the background noise sound pressure level inside the mute compartment.
CN202211009620.2A 2022-07-28 2022-08-22 Method for measuring acoustic performance of mute chamber Pending CN115389631A (en)

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CN202210896406 2022-07-28
CN2022108964067 2022-07-28

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