A method for measuring the acoustic performance of a soundproof cabin

Abstract

The present invention relates to a method for measuring the acoustic performance of a silent cabin, wherein a closed cabin is used to isolate the room where the silent cabin is placed and the interior of the silent cabin into two independent acoustic environments, and two non-directional sound sources, six external measuring points and three external measuring points in the silent cabin are used to excite the sound field in the room, and the room is used as a sound-generating room for sound insulation testing, and the silent cabin is used as a sound-receiving room. The silent cabin is placed in a reverberant sound field as much as possible, the accuracy of the measurement data is improved, and a basis is provided for silent cabin manufacturers to design silent cabins with different acoustic performances.

Description

Technical Field

[0001] The invention relates to a method for measuring the acoustic performance of a soundproof cabin. Background Art

[0002] The acoustic environment in a soundproof cabin directly affects the comfort of the people inside, and is a key factor in ensuring or even improving the market competitiveness of the soundproof cabin industry. The acoustic environment in a soundproof cabin is closely related to the sound insulation performance of the panel walls, the sealing performance, and the noise level of the ventilation system. Selecting a suitable measurement method to test the acoustic performance of the soundproof cabin can provide effective data support for the sound insulation design, sealing treatment, and ventilation system design of the soundproof cabin. Existing laboratory sound insulation methods often only target individual cabin wall panel samples, and cannot measure the overall sound insulation performance of the cabin, and the sound insulation performance measurement method cannot fully characterize the acoustic performance of the soundproof cabin, so the content of the present invention is to solve the above problems. Summary of the invention

[0003] The purpose of the present invention is to provide a method for measuring the acoustic performance of a soundproof cabin, thereby solving the problem of testing the acoustic performance of a soundproof cabin.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] The present invention provides a method for measuring the acoustic performance of a soundproof cabin, which comprises the following steps:

[0006] S1: Place the sealed silent cabin asymmetrically on the floor of the measurement room and not parallel to any wall in the measurement room.

[0007] S2: Turn off the effective sound-generating components in the silent cabin and turn on the ventilation system in the silent cabin at the same time.

[0008] S3: Two sound-raising points are evenly arranged on the periphery of the silent cabin. The distance between the sound-raising points should be at least 3.0m, and the distance between the silent cabin and the sound-raising points should not be less than 2.0m;

[0009] S4: Six external measuring points are arranged outside the sound-speaking point, the height of the external measuring points from the ground is greater than 1.2m, and the distance between the external measuring points and any surface of the measurement room and the silent cabin is not less than 1.0m;

[0010] S5: Three internal measuring points are set in the silent cabin. The three internal measuring points are distributed on a sphere with a radius of 0.3m and a center at the operator's hearing position. The three measuring points are located with reference to the positions of the operator's nose and ears. The height of all internal measuring points from the ground is greater than 1.2m;

[0011] S6: Measure the sound pressure level of the background noise in the quiet cabin. Place the sound level meter at the inner measuring point, and the distance between the sound level meter and the ground of the quiet cabin should be greater than 1.2m. Close the door of the quiet cabin, measure the background noise of the quiet cabin, measure twice at each position, and save the data.

[0012] S7: Measure the sound pressure level in the room. Adjust the height of the speaker point so that it is greater than 1.5m from the floor of the room. Place the sound level meter on the external measuring point, turn on the speaker, and measure the sound pressure level of the speaker in the room. Measure once at each position and save the data.

[0013] S8: Measure the sound pressure level in the silent cabin. Place the sound level meter at the inner measuring point, and the distance between the sound level meter and the ground of the silent cabin should be greater than 1.2m. Turn on the speaker, close the door of the silent cabin, and measure the sound pressure level in the silent cabin. Measure twice at each position and save the data.

[0014] S9: Measurement of the sound pressure level of ventilation equipment noise. Adjust the height of the speaker point so that it is greater than 1.2m from the floor of the room. Place the sound level meter on the inner measuring point. Turn on the ventilation equipment and open all gears in sequence. Close the door of the silent cabin and measure the sound pressure level of the ventilation equipment noise. Measure each position twice and save the data.

[0015] S10: Sound leakage detection of the silent cabin, sound leakage detection of the edge seams of the silent cabin; after the detection is completed, the sound image is exported.

[0016] S11: Calculate the data and then rate it. The rating includes the evaluation and grading of the sound insulation performance of the quiet cabin and the evaluation and grading of the noise level of the ventilation system of the quiet cabin.

[0017] Preferably, all movable parts of the silent cabin should be operated at least 10 times before measurement.

[0018] Preferably, the minimum distance between the speaker and the nearest sound level meter is not less than 0.3V 1 / 3 , where V is the volume of the room.

[0019] Preferably, the spacing between the outer measuring points is not less than λ / 2, where λ is the wavelength of the center frequency of the lowest octave band within the test frequency range.

[0020] Preferably, the data where the difference between the background noise sound pressure level inside the silent cabin in S6 and the sound pressure level inside the silent cabin with the loudspeaker turned on in S8 is between 10 dB and 15 dB is corrected.

[0021] Furthermore, the corrected formula is L p =10log 10 (10 Lsb / 10 -10 Lb / 10 ) where L p is the corrected sound pressure level of the loudspeaker, where 10 Lsbis the sound pressure level in the silent cabin when the speaker is turned on, L b It is the background noise sound pressure level inside the quiet cabin.

[0022] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0023] The present invention relates to a method for measuring the acoustic performance of a silent cabin. This patent innovatively proposes a method for measuring the sound insulation performance of a silent cabin, measuring the ventilation system, and detecting sound leakage in the cabin. The method is suitable for laboratory and field measurements of silent cabins. The closed cabin is used to isolate the room where the silent cabin is placed and the interior of the silent cabin into two independent acoustic environments. The room is used as a sound-generating room for sound insulation testing, and the silent cabin is used as a sound-receiving room. The entire silent cabin is used as a test specimen. The requirements for the placement of the silent cabin, as well as two non-directional sound sources for sound field excitation in the room, six external measuring points, and three internal measuring points in the silent cabin are given. When the test points are specifically arranged, the silent cabin is placed in the reverberant sound field as much as possible to improve the accuracy of the measurement data. This patent also innovatively provides a silent cabin sound insulation performance evaluation grading and a silent cabin ventilation system noise evaluation grading through experimental tests and experience summarization of different silent cabins, providing a basis for silent cabin manufacturers to design silent cabins with different acoustic performances. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of the layout principle of the measurement points placed in the silent cabin close to the room wall;

[0026] Figure 2 This is a schematic diagram of the layout principle of the measurement points when the silent cabin is not placed close to the room wall;

[0027] Figure 3 It is the evaluation and grading of the sound insulation performance of the quiet cabin;

[0028] Figure 4 It is an evaluation and grading of the noise level of the ventilation equipment in the silent cabin.

[0029] The reference numerals are described as follows:

[0030] 1. Quiet cabin;

[0031] 2. Room walls;

[0032] 3. Loudspeaker point; 4. External measuring point; 5. Internal measuring point. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] This example is about the measurement method of the acoustic performance of a soundproof cabin, which is an enclosure specially designed to protect people from noise interference.

[0037] The present invention comprises the following steps:

[0038] S1: Place the silent cabin 1 asymmetrically on the floor of the measurement room and not parallel to any wall in the measurement room. The reason is that a parallel setting may generate resonance and other additional noise. It can be close to the room wall 2 or not. Figure 1 and Figure 2 Shown are the different placement positions of the silent cabin.

[0039] S2: Turn off the effective sound-generating components in the silent cabin 1 and simultaneously turn on the ventilation system in the silent cabin, such as an exhaust fan, etc.;

[0040] S3: Two sound-enhancing points are evenly arranged on the periphery of the silent cabin 1. The distance between the sound-enhancing points should be at least 3.0m, and the distance between the silent cabin 1 and the sound-enhancing point 3 should not be less than 2.0m; avoid being close to the surface and corners of the measurement room; a loudspeaker can be moved between the selected positions to emit sound in sequence to form two sound-enhancing points; or two unrelated loudspeakers can be operated simultaneously to emit sound separately.

[0041] S4: Six external measuring points 4 are set outside the speaker point 3, evenly distributed around the silent cabin 1. The height of the external measuring point 4 from the ground is greater than 1.2m, and the distance between the external measuring point 4 and any surface of the measurement room and the silent cabin 1 is not less than 1.0m; the minimum distance between the speaker 3 and the external 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 ) The spacing between the external measuring points 4 is not less than λ / 2, where λ is the wavelength of the center frequency of the lowest octave band within the test frequency range, and λ is generally 3.4m.

[0042] S5: Three inner points 5 are set in the silent cabin 1. The positions of the three inner points 5 are distributed on a circular surface with a radius of 0.3. The center of the circular surface is on a spherical surface at the operator's hearing position. The positions of the three measuring points refer to the positions of the operator's nose and ears. The height of all inner points 5 from the ground is greater than 1.2m;

[0043] The number of loudspeakers (sound source positions) should be greater than or equal to the maximum octave deviation DP′ between any two sound source positions (for example, at a sound frequency of 100 Hz, the sound pressure level at speaker position 1 is 74 dB, and at position 2 is 76 dB, then the deviation value = 2), and the number of positions should not be less than two, and the distance between them is set in this way to diffuse the sound field components in the room (that is, the sound pressure levels in various places in the room are not much different).

[0044] The number of external measuring points is set to fully collect the sound pressure level data of the external sound field, and the six positions are set to make the microphone position within the diffuse sound field;

[0045] The number of internal measuring points is determined according to the number of a mouth and two ears of the human body, and the three positions are set according to the height of the sitting posture and the positions of the mouth and two ears of the human body.

[0046] S6: Measure the background noise in the silent cabin. Place the sound level meter at the inner measuring point 5. The distance between the sound level meter and the ground of the silent cabin should be greater than 1.2m. After closing the door of the silent cabin, measure the background noise of the silent cabin. Measure twice at each position and save the data.

[0047] S7: Measure the sound pressure level in the room. Adjust the height of the speaker point so that it is greater than 1.5m from the floor of the room. Place the sound level meter at the external measuring point 4. Turn on the speaker and measure the sound pressure level of the speaker in the room. Measure each position once and save the data.

[0048] S8: Measure the sound pressure level in the silent cabin. Place the sound level meter at the inner measuring point 5. The distance between the sound level meter and the ground of the silent cabin should be greater than 1.2m. Turn on the speaker, close the door of the silent cabin, and measure the sound pressure level in the silent cabin. Measure twice at each position and save the data.

[0049] S9: For ventilation equipment noise measurement, place the sound level meter at the inner measuring point 5, and the sound level meter should be more than 1.2m away from the ground of the silent cabin. Turn on the ventilation equipment and open all gears in sequence, and close the door of the silent cabin to measure the noise sound pressure level of the ventilation equipment. Measure each position twice and save the data.

[0050] S10: Sound leakage detection of the silent cabin, use the vector sound brush device to detect the sound leakage of the side seams at the bottom of the silent cabin; after the detection, the sound image is exported. The sound image is intended to show the airtightness of the silent cabin.

[0051] S11: All the data recorded above are statistically calculated and then graded. The rating includes the evaluation and grading of the sound insulation performance of the silent cabin and the evaluation and grading of the noise level of the ventilation system of the silent cabin.

[0052] In S7, the sound pressure level of the background noise in the silent cabin in each frequency band is at least 10 dB lower than the sound pressure level caused by the noise source (the noise source in this example is the speaker) in the silent cabin, and preferably lower than 15 dB.

[0053] If the difference is between (10dB and 15dB), the correction of the sound pressure level in each frequency band is calculated as follows (no correction is required if the difference is greater than 15dB): The correction formula is:

[0054]

[0055] L p - Corrected sound pressure level of the quiet cabin;

[0056] L sb ——The sound pressure level of the static pressure cabin when the loudspeaker is turned on;

[0057] L b ——Background noise sound pressure level of static pressure cabin. The above units are all dB;

[0058] The average sound pressure level in a room or a soundproof cabin is calculated as follows:

[0059]

[0060] - the average sound pressure level in a room or a soundproof cabin;

[0061] L′ p ——Sound pressure level at each measuring point in the room or silent cabin; all the above units are dB;

[0062] n——Number of measurements.

[0063] Sound pressure insulation value D of the silent cabin p Calculate as follows:

[0064] D p=(L p ) room -(L p ) cabin

[0065] Dp——sound pressure sound insulation value, unit: dB;

[0066] (L p ) room ——the average sound pressure level in each frequency band in the room;

[0067] (L p ) cabin ——Average sound pressure level in each frequency band in the silent cabin.

[0068] Equivalent continuous A sound level L for ventilation equipment Aeq，T Calculate as follows:

[0069]

[0070] L Aeq，T - equivalent continuous A sound level of ventilation equipment;

[0071] L PA′ ——Sound pressure level of the selected frequency in the 1 / 3 octave band; the above units are dB(A);

[0072] n is the number of selected frequencies in the 1 / 3 octave frequency band.

[0073] The sound insulation performance of the silent cabin is evaluated and graded into 5 levels. The basis of the grading is the calculated D p The range of the single-value evaluation quantity for each level is referred to Figure 3 shown.

[0074] Then the noise level of the ventilation equipment in the silent cabin is evaluated and graded. The evaluation should be divided into 3 levels. The basis of the classification is the calculated L Aeq，T The range of the single-value evaluation quantity for each level is referred to Figure 4 shown.

[0075] In summary, this patent innovatively proposes a method for measuring the sound insulation performance of a silent cabin, measuring the ventilation system, and detecting the sound leakage of the cabin. The closed cabin is used to isolate the room where the silent cabin is placed and the interior of the silent cabin into two independent acoustic environments. The room is used as a sound-generating room for sound insulation testing, and the silent cabin is used as a sound-receiving room. The entire silent cabin is used as a test specimen, and the requirements for the placement of the silent cabin are given to try to place the silent cabin in the reverberant sound field to improve the accuracy of the measurement data. Through experimental testing and experience summary of different silent cabins, the patent innovatively provides a classification of the sound insulation performance of the silent cabin and a classification of the noise level of the ventilation system of the silent cabin, providing a basis for silent cabin manufacturers to design silent cabins with different acoustic performance. It is suitable for the overall sound insulation of the cabin and is suitable for different occasions. It solves the problem that the laboratory sound insulation method can only test a single component. The test equipment is easy to meet and the operation steps are simple and easy to understand.

[0076] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for measuring the acoustic performance of a soundproof cabin, characterized in that: It includes the following steps: S1: Place the silent cabin asymmetrically on the floor of the measurement room and not parallel to any wall in the measurement room. S2: Turn off the effective sound-generating components in the silent cabin and turn on the ventilation system in the silent cabin at the same time. S3: Two sound-raising points are evenly arranged on the periphery of the silent cabin. The distance between the sound-raising points should be at least 3.0m, and the distance between the silent cabin and the sound-raising points should not be less than 2.0m; S4: Six external measuring points are arranged outside the sound-speaking point, the height of the external measuring points from the ground is greater than 1.2m, and the distance between the external measuring points and any surface of the measurement room and the silent cabin is not less than 1.0m; S5: Three internal measuring points are set in the silent cabin. The three internal measuring points are distributed on a circular surface with a radius of 0.3 m. The three internal measuring points are located with reference to the positions of the nose and ears of the operator. The height of the internal measuring points from the ground is greater than 1.2 m. S6: Measure the sound pressure level of background noise in the quiet cabin. Place the sound level meter at the inner measuring point, and the distance between the sound level meter and the ground of the quiet cabin should be greater than 1.2m. Close the door of the quiet cabin and measure the sound pressure level of background noise in the quiet cabin. Measure twice at each position and save the data. S7: Measure the sound pressure level in the room. Adjust the height of the speaker point so that it is greater than 1.5m from the floor of the room. Place the sound level meter on the external measuring point, turn on the speaker, and measure the sound pressure level of the speaker in the room. Measure once at each position and save the data. S8: Measure the sound pressure level in the silent cabin. Place the sound level meter at the inner measuring point, and the distance between the sound level meter and the ground of the silent cabin should be greater than 1.2m. Turn on the speaker, close the door of the silent cabin, and measure the sound pressure level in the silent cabin. Measure twice at each position and save the data. S9: Measurement of the sound pressure level of ventilation equipment noise. Adjust the height of the speaker point so that it is greater than 1.2m from the floor of the room. Place the sound level meter on the inner measuring point. Turn on the ventilation equipment and open all gears in sequence. Close the door of the silent cabin and measure the sound pressure level of the ventilation equipment noise. Measure each position twice and save the data. S10: Sound leakage detection of the silent cabin, sound leakage detection of the bottom seams of the silent cabin; After the test is completed, the sonogram is exported; S11: Calculate the data and then rate it. The rating includes the evaluation and grading of the sound insulation performance of the quiet cabin and the evaluation and grading of the noise level of the ventilation system of the quiet cabin; The minimum distance between the speaker and the nearest sound level meter is not less than 0.3V 1 / 3 , where V is the volume of the room, the spacing between the external measuring points is not less than λ / 2, and λ is the wavelength of the center frequency of the lowest octave band within the test frequency range.

2. The method for measuring the acoustic performance of a soundproof cabin according to claim 1, characterized in that: Before measurement, all movable parts of the cabin should be operated at least 10 times.

3. The method for measuring the acoustic performance of a soundproof cabin according to claim 1, characterized in that: The data of the difference between the background noise sound pressure level inside the silent cabin in S6 and the sound pressure level inside the silent cabin with the loudspeaker turned on in S8, which is between 10dB and 15dB, are corrected.

4. The method for measuring the acoustic performance of a soundproof cabin according to claim 3, characterized in that: The corrected formula is L p =10log 10 (10 Lsb / 10 -10 Lb / 10 )Where L p is the corrected sound pressure level of the loudspeaker, where 10 Lsb is the sound pressure level in the silent cabin when the speaker is turned on, L b It is the background noise sound pressure level inside the quiet cabin.

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