JP5888011B2 - Transmission characteristic generation method for sound insulation measurement, transmission characteristic generation apparatus for sound insulation measurement, sound insulation measurement method, and sound insulation measurement apparatus - Google Patents

Description

  The present invention relates to a transmission characteristic generation method for sound insulation measurement, a transmission characteristic generation device for sound insulation measurement, a sound insulation measurement method, and a sound insulation measurement apparatus.

  In a conventional gasoline vehicle, a sound insulation member and a sound absorption member are provided on the vehicle body in order to suppress noise from an engine or the like from entering the vehicle interior. It is necessary to quantitatively evaluate how much the noise intrusion is suppressed by the sound insulating member and the sound absorbing member using a performance index called sound insulating performance.

  As a general method used when measuring the sound insulation performance of a vehicle, there is a method of measuring the sound insulation performance using a reciprocity theorem. The reciprocity theorem is that the received sound level by the received sound source does not change even if the positions of the sound source and the received sound source are reversed. For example, a speaker that outputs sound equivalent to noise is disposed in the vehicle interior, a microphone is disposed in the engine portion, and a transfer function of sound transmitted from the speaker to the microphone is measured.

  In the case of the above method, the microphone is attached to a noise generating component such as an engine. Since the noise generating parts are arranged in different parts of the vehicle, the speaker needs to have the property of transmitting sound at the same sound level in any direction, like a point sound source. If there is directivity instead of a point sound source, the transmitted sound level varies depending on the direction of the speaker or the position of the noise component, and the sound insulation performance cannot be measured quantitatively.

  Loudspeaker vibration can occur on a surface but not on a point. For this reason, speakers are not strictly point sources. However, when the sound output from the speaker has a low frequency of several thousand Hz or less, the sound diffused from the speaker to the surroundings has almost no directivity and can be regarded as a point sound source. For example, low-frequency sound equivalent to engine noise has little directivity, so if you output low-frequency sound from an existing speaker, the speaker will behave like a point sound source and measure the sound insulation performance against engine noise it can. Further, as a method for evaluating the sound insulation performance of a vehicle, for example, as in Patent Document 1, a technique for strictly calculating using a finite element method is also known.

JP 2010-230484 A

  In recent years, various automobile manufacturers have developed vehicles that use a motor such as EV and HEV as a driving force. High-frequency noise over 10 KHZ, which is not found in vehicles driven only by engines from motors, inverters, DC / DC converters, batteries and the like mounted on these vehicles, has become a problem. In vehicle design, in order to predict in advance the sound pressure level when noise generated from these parts arrives in the passenger compartment, the sound function at each part is measured by measuring the transfer function from the sound source to the receiving point. Allocating the target value of the pressure level and evaluating the achievement level of the completed vehicle, it is required to measure the sound insulation performance with high accuracy in the high frequency range as well.

  Here, a high frequency sound, for example, a sound of 10 kHz or higher, has directivity different from a low frequency, and does not behave like a point sound source like the low frequency described above. Therefore, when a speaker that outputs sound equivalent to motor noise is placed in the vehicle compartment and a microphone is placed in the motor part, the sound reception level of the microphone will change if the distance between the speaker and the microphone or the relative posture changes. End up. For high-frequency sound, there is a problem that the conventional sound insulation performance measuring method in which the speaker is regarded as a point sound source cannot be used.

  Moreover, when analyzing using a finite element method like patent document 1, there exists a problem that calculation amount will be enormous and processing will take much time.

  The present invention has been made in view of the above circumstances, and provides a method for generating a transmission characteristic for sound insulation measurement and a transmission for sound insulation degree measurement that enables measurement of sound insulation performance for high-frequency components without enormous amount of computation. It is an object to provide a characteristic generation device, a sound insulation degree measuring method, and a sound insulation degree measurement device.

In order to achieve the above object, a method for generating a transmission characteristic for measuring sound insulation according to the present invention includes a rigid body having a plurality of first virtual points and a plurality of second virtual bodies arranged three-dimensionally apart from the rigid body by a predetermined distance. virtually a point, the sound of one of the first virtual point and the second virtual point, a sound source for generating sound, and the other, as a sound receiving source for sound receiving sound, to the sound reception source from the sound source a first step of the transfer characteristic, by using a transfer function simulation, the a rigid, virtually and a plurality of third virtual point which is arranged on the same plane with a predetermined distance away from the rigid, said first one of the virtual point and the third virtual point, a sound source for generating sound, and the other, as a sound receiving source for sound receiving sound, a transfer characteristics of the sound from the sound source to the sound receiving source, by using a transfer function a second step of the simulation, a first virtual point of the rigid A speaker having a plurality of sound sources arranged in a positional relationship Flip, and a microphone for sound reception sound from the speaker in the same position as the plurality of the third virtual point for the rigid, and at least the speaker the microphone prepared for unobstructed space between the sound generated from the speaker and the sound reception by the microphone, and a third step of detecting a transfer characteristic of the sound from the speaker, detected in the third step as consistent with been transfer characteristics, the fourth step of calculating a correction value for correcting the simulated transfer characteristic at the second step, based on the correction value calculated in the fourth step, the The sound transfer characteristic calculated in the first step is corrected to generate a sound insulation degree measurement transfer characteristic.

In order to achieve the above object, a transmission characteristic generating apparatus for measuring sound insulation according to the present invention includes a speaker, a microphone, and a control unit. The speaker has a plurality of sound sources. The microphone receives sound from the speaker and measures the sound level. The control unit controls the speaker and the microphone and simulates a sound transmission characteristic. Further, the control unit includes a rigid body having a plurality of first virtual point, from said rigid body a predetermined distance apart and virtual and a plurality of second virtual point which is arranged three-dimensionally, wherein the first virtual point and the second one of the two virtual point, a sound source for generating sound, and the other, as a sound receiving source for sound receiving sound, a transfer characteristics of the sound from the sound source to the sound receiving source, and simulation using the transfer function, the rigid And a plurality of third virtual points arranged on the same plane at a predetermined distance from the rigid body , and one of the first virtual point and the third virtual point is a sound source that generates sound, the other, as a sound receiving source for sound receiving sound, a transfer characteristics of the sound from the sound source to the sound receiving source, and simulation using the transfer function, a plurality of the speakers in the same positional relationship as the first virtual point of the rigid With the sound source placed against the rigid body Sounds from the speakers are received by the microphones arranged in the same posture as the plurality of the third virtual points, and the transmission characteristics of the sounds from the speakers are detected, so as to match the detected transmission characteristics the first a simulated transfer characteristics between the virtual point and said third virtual point calculates a correction value for correcting, based on the calculated correction value, the said first virtual point second Sound transfer characteristics obtained as a result of simulation with virtual points are corrected to generate a sound insulation degree measurement transfer characteristic.

In order to achieve the above object, the sound insulation degree measuring method according to the present invention is configured to measure the reception level of the speaker and microphone installed in the measurement environment by receiving sound from the speaker through the microphone. , the positional relationship between the speaker and the microphone, virtual sound receiving and sound insulation measurement for transmission characteristics described above, based on the, the sound reception at the microphone when there is no obstacle between the speaker and the microphone level is calculated, and the sound receiving level measured in said measuring step, a virtual sound receiving level calculated in the calculating step, on the basis, calculates the sound insulation degree.

In order to achieve the above object, a sound insulation degree measuring apparatus according to the present invention includes a speaker, a microphone, and a control unit. The speaker has a plurality of sound sources. The microphone receives sound from the speaker and measures the sound level. The control unit receives the microphone when there is no obstacle between the speaker and the microphone based on the positional relationship between the speaker and the microphone and the transmission characteristic for sound insulation measurement according to claim 1. calculating a virtual sound receiving levels sound, and calculated the virtual sound receiving level, a sound level measured by the microphone, on the basis of the calculated sound insulation degree.

  According to the transmission characteristic generation method for sound insulation measurement and the transmission characteristic generation device for sound insulation measurement, the transmission characteristic of sound from the speaker is generated based on the simulation result and the measurement result, so that the transmission characteristic behaves like a point sound source. Even if it is not, the characteristics can be accurately reproduced. Since the sound propagation equation around the hard sphere is used for the simulation of the transfer characteristic, the transfer characteristic can be obtained without requiring a complicated calculation as in the finite element method.

  According to the sound insulation level measurement method and the sound insulation level measurement device, a virtual sound reception level at which sound is not reduced by an obstacle is calculated based on the positional relationship between the speaker and the microphone and the transmission characteristic for sound insulation measurement. By comparing with, the sound insulation degree can be calculated quantitatively.

It is a block diagram which shows schematic structure of a sound-insulation degree measuring apparatus. It is a figure which shows the external appearance of a speaker. It is a figure which shows a mode that the transmission characteristic of the sound of a speaker is measured. It is a figure which shows the measurement result of the transfer characteristic of a speaker. It is a flowchart which shows the procedure which produces | generates the transfer characteristic for sound insulation degree measurement. It is a figure which shows the sound source and receiving sound source at the time of carrying out the three-dimensional simulation of the transmission characteristic of sound. It is a figure which shows the sound source and receiving sound source at the time of carrying out the plane simulation of the transfer characteristic of sound. It is a figure showing the comparison with the simulation result and measurement result of a sound transmission characteristic. It is a figure which shows a mode that the microphone and speaker of the sound-insulation degree measuring apparatus were installed in the vehicle. It is a flowchart which shows the flow of a sound-insulation degree measurement procedure.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

  FIG. 1 is a block diagram showing a schematic configuration of a sound insulation degree measuring apparatus, and FIG. 2 is a view showing an appearance of a speaker.

  The sound insulation degree measuring apparatus 1 of this embodiment is an apparatus for measuring the degree of sound insulation of noise generated from noise components. In the present embodiment, an example in which the sound insulation degree measuring apparatus 1 measures the sound insulation degree of a noise component in a vehicle will be described.

  The sound insulation level measuring apparatus 1 includes a speaker 10, a microphone 20, a storage unit 30, and a control unit 40.

  The speaker 10 has a plurality of sound sources. For example, as shown in FIG. 2, the speaker 10 has a sound source on each face of a regular dodecahedron and generates sound from each sound source. The microphone 20 receives sound from the speaker 10 and measures the sound level.

  The storage unit 30 stores sound data generated by the speaker 10 and sound reception data received by the microphone 20. The storage unit 30 also stores the result of simulation analysis of received sound data, transfer characteristics used for measuring the sound insulation level, and the like. The control unit 40 controls the speaker 10, the microphone 20, and the storage unit 30.

(Transfer characteristics)
Before describing the specific operation flow of the sound insulation level measuring apparatus 1 of the present embodiment, the characteristics (hereinafter referred to as transfer characteristics) of transmitting the sound from the speaker 10 will be described.

  FIG. 3 is a diagram showing how the sound transmission characteristics of the speakers are measured, and FIG. 4 is a diagram showing the measurement results of the speaker transmission characteristics.

  When measuring the sound transmission characteristics in the planar direction of the speaker 10, a receiving sound source such as a microphone 20 is disposed around the speaker 10 at a position indicated by a black circle in FIG. 2. However, as shown in FIG. 2, it takes man-hours and costs to install the microphones 20 at a plurality of positions. Therefore, as shown in FIG. 3, the microphone 20 and the speaker 10 are arranged apart from each other by a predetermined distance, and the microphone 20 receives sound by the microphone 20 each time the speaker 10 is rotated by a predetermined angle. The same situation can be realized. For example, each time the speaker 10 that is 3 m away from the microphone 20 is rotated once, the sound level received by the microphone 20 is measured and the values between the angles are complemented. .

  In FIG. 4, the transfer characteristic when a sound of 1 kHz or 10 kHz is generated from the speaker 10 is indicated by a solid line, and the transfer characteristic when a point sound source is assumed is indicated by a one-dot chain line. In the case of 1 kHz, as shown on the left side in the figure, an acoustic level of about 10 dB is obtained in any direction of 360 degrees, and there is no distortion in the transfer characteristics. Further, in the case of 1 kHz, the transfer characteristics of the speaker 10 substantially coincide with the transfer characteristics of the point sound source. On the other hand, in the case of 10 kHz, as shown on the right side in the figure, it can be seen that the sound level varies depending on the position, and the transfer characteristics are distorted. In the case of 10 kHz, the transfer characteristic of the speaker 10 is significantly different from the transfer characteristic of a point sound source having an omnidirectional of about 5 dB. Thus, when the speaker 10 is configured as a polyhedron, the speaker 10 behaves like a point sound source at a frequency of about 1 kHz, and has a completely different transfer characteristic from a point sound source at a high frequency of 10 kHz or more.

  The sound insulation degree measuring apparatus 1 of the present embodiment measures the sound insulation performance of the high frequency noise component using the speaker 10 while taking into account that the transmission characteristics from the speaker 10 are distorted when the frequency becomes high.

(Generation of transmission characteristics for sound insulation measurement)
Before actually applying the sound insulation degree measuring apparatus 1 to a vehicle, a procedure for generating a transfer characteristic serving as a reference for measuring the sound insulation degree will be described.

  FIG. 5 is a flowchart showing a procedure for generating a transmission characteristic for measuring sound insulation, FIG. 6 is a diagram showing a sound source and a receiving sound source when a three-dimensional simulation of a sound transmission characteristic is performed, and FIG. FIG. 8 is a diagram showing a comparison between a simulation result of a sound transfer characteristic and a measurement result. 5 is executed by the control unit 40 according to the application stored in the storage unit 30.

  The control unit 40 simulates transfer characteristics when high frequency sound is generated from the speaker 10 (step S1). Here, as shown in FIG. 6, a hard sphere 50 having a plurality of first virtual points 12 and a plurality of second virtual points 22 arranged at an equiangular angle apart from the hard sphere 50 by a free sound. It is virtual on the ground. The simulation does not consider configurations that absorb or reflect sound. The hard sphere 50 corresponds to the speaker 10, the first virtual point 12 is arranged in the same positional relationship as the sound source on the speaker 10, and the second virtual point 22 corresponds to the microphone 20 that is a receiving sound source. The second virtual point 22 is 3 m away from the hard sphere 50. The control unit 40 calculates the sound level when sound is generated at the first virtual point 12 and received at the second virtual point 22, and the transfer characteristics are simulated by complementing between the second virtual points 22. .

  Here, in order to calculate the acoustic level, the following sound propagation formula (1) around the hard sphere is used.

Pn (x) is a Legendre function,
hn ⁽²⁾ (x) is a second-type sphere Hankel function,
k is the wave number.

  Since the first virtual points 12 are arranged point-symmetrically on the hard sphere 50, it is sufficient to arrange the second virtual points 22 on the hemisphere side as shown in FIG.

  Next, the control unit 40 simulates transfer characteristics when high-frequency sound is generated from the speaker 10 (step S2). Here, as shown in FIG. 7, a hard sphere 50 having a plurality of first virtual points 12, and a plurality of third virtual points 24 arranged equiangularly on the same plane at a predetermined distance from the hard sphere 50. Is virtual. The simulation does not consider configurations that absorb or reflect sound. The hard sphere 50 and the first virtual point 12 are the same as in FIG. 6, and the third virtual point 24 corresponds to the microphone 20 that is a sound receiving source. The third virtual point 24 is 3 m away from the hard sphere 50. The control unit 40 calculates the sound level when sound is generated at the first virtual point 12 and received at the third virtual point 24, and the transfer characteristics are simulated by complementing between the third virtual points 24. . The simulation result is, for example, as shown by a one-dot chain line in FIG.

  Subsequently, the control unit 40 controls the microphone 20 and the speaker 10 that are actually arranged, receives sound from the speaker 10 by the microphone 20, and detects transfer characteristics (step S3). Here, the microphone 20 is disposed on the same plane with respect to the speaker 10 in the same posture as the third virtual point with respect to the hard sphere 50 in step S2. As shown in FIG. 3, by rotating the speaker 10 at a position 3 m away from the microphone 20, the same condition as when the plurality of microphones 20 are on a plane around the speaker 10 can be realized. A plurality of microphones 20 may actually be arranged as shown in FIG. The speaker 10 and the microphone 20 are arranged at least in a space where there is no obstacle, preferably in an anechoic room. The detected transfer characteristic is, for example, as shown by a solid line in FIG. As shown in FIG. 8, the detected transfer characteristic has a distortion similar to the transfer characteristic obtained by calculation in step S2.

  The control unit 40 calculates a correction value (correction term) for correcting the transfer characteristic simulated in step S2 so as to match the actual transfer characteristic detected in step S3 (step S4).

  Subsequently, the control unit 40 corrects the transfer characteristic obtained by the calculation in Step S1 using the correction value obtained in Step S4, and generates the sound insulation degree measurement transfer characteristic (Step S5). The generated transmission characteristic for measuring sound insulation is stored in the storage unit 30. The transmission characteristic for sound insulation measurement generated in step S5 indicates the sound level received by the microphone 20 (received sound source) in an arbitrary direction and distance from the speaker 10 (rigid sphere) in the anechoic space. That is, according to the transmission characteristic for measuring the sound insulation degree, if the posture of the speaker 10 and the position of the microphone 20 are accurately given, the sound level received by the microphone 20 can be estimated.

  In step S1 and step S2 described above, the simulation is performed when the distance between the first virtual point 12 and the second virtual point 22 or the third virtual point 24 is 3 m. However, any distance other than 3 m can be set. Regardless of which distance is set, once the transmission characteristic for sound insulation measurement is obtained, the sound level can be estimated at any distance and direction from the sound source in consideration of sound attenuation and diffusion.

(Sound insulation measurement)
Next, a procedure for measuring the sound insulation degree by the sound insulation degree measuring apparatus 1 will be described.

  FIG. 9 is a diagram showing a state in which the microphone and speaker of the sound insulation degree measuring apparatus are installed in the vehicle, and FIG. 10 is a flowchart showing the flow of the sound insulation degree measurement procedure. Note that the procedure of the flowchart shown in FIG. 10 is executed by the control unit 40 in accordance with the application stored in the storage unit 30.

  As shown in FIG. 9, the speaker 10 is disposed in the vehicle interior space. The speaker 10 is installed in, for example, the position of the driver's face in the driver's seat, the passenger seat, the rear seat, and the like. The microphone 20 is installed in the vicinity of the inverter 60 and the DC / DC converter 62 in the vehicle body. The sound insulation level is measured for each microphone 20. The posture of the speaker 10 and the position of the microphone 20 with respect to the speaker 10 are known and stored in the storage unit 30 in advance. Further, the storage unit 30 of the sound insulation level measuring device 1 stores a sound having the same frequency as the noise generated from the inverter 60 and the DC / DC converter 62.

  As illustrated in FIG. 10, the control unit 40 generates sound having the same frequency as the measurement target using the speaker 10, collects sound using the microphone 20, and measures the sound level of the collected sound (step S <b> 11).

  Based on the transmission characteristics for sound insulation measurement generated by the procedure of FIG. 5 and the positional relationship between the speaker 10 and the microphone 20, the control unit 40 uses the microphone when the speaker and the microphone are in the anechoic space with the same positional relationship. A virtual sound level to be received is calculated (step S12). The virtual sound level indicates the sound level when there is no sound insulation or sound absorption member in the vehicle body.

  The control unit 40 divides the sound level measured in step S11 by the virtual sound level calculated in step S12 and calculates the sound insulation degree (step S13).

  As described above, according to the present embodiment, the sound transmission characteristic (sound insulation degree measurement transmission characteristic) from the speaker 10 is generated based on the simulation result and the measurement result. It can be accurately reproduced by the transmission characteristics for measuring sound insulation.

  Since the virtual sound level calculated using the transmission characteristic for sound insulation level measurement is compared with the sound level actually detected by the microphone 20, the sound insulation level can be measured quantitatively. In other words, as the sound level actually detected by the microphone 20 varies depending on the position, the virtual sound level varies at a position corresponding to the sound insulation degree measurement transfer characteristic. For example, at a position where the measurable sound level becomes large, the virtual sound level calculated by the sound insulation degree measurement transfer characteristic also becomes large. Since the acoustic level and the virtual acoustic level increase or decrease at the same rate, by dividing them from each other, it is possible to measure a quantitative sound insulation level by removing the magnitude of the acoustic level due to distortion.

  In addition, since the transfer characteristic is simulated using the transfer function equation (1), there is less complicated calculation than when the finite element method is adopted, and the sound insulation degree can be measured quickly.

  In step S <b> 1 for generating the transmission characteristic for sound insulation measurement, a plurality of second virtual points 22 are arranged at equiangular angles, so that it is easy to complement the second virtual points 22. In step S2, since the plurality of third virtual points 24 are arranged equiangularly on the same plane, the space between the third virtual points 24 can be easily complemented.

  In the above-described embodiment, the case where the first virtual point 12 corresponds to the sound source and the second virtual point 22 corresponds to the receiving sound source in Step S1 for generating the transmission characteristic for sound insulation measurement has been described. It is not limited to this. The transfer characteristics may be calculated assuming that the first virtual point 12 corresponds to a receiving sound source arranged in the same positional relationship as the sound source on the speaker 10 and the second virtual point 22 corresponds to a sound source. According to the reciprocity theorem, in the free sound field, the same characteristics can be obtained regardless of which of the first virtual point 12 and the second virtual point 22 is a sound source and a sound source. The same applies to step S2.

  In the above embodiment, the regular dodecahedron speaker 10 is illustrated, but the present invention is not limited to this. Any regular polyhedral speaker may be applied. However, as the number of surfaces increases, the size of speakers that can be arranged on one surface also decreases. Therefore, the number of surfaces is limited in consideration of securing the minimum sound level for measuring the sound insulation level.

  In the above embodiment, the case of measuring the sound insulation level in the vehicle has been described. However, it is not limited to this. The present invention can be applied to the measurement of the sound insulation degree in any equipment, apparatus, and environment.

1 Sound insulation measuring device,
10 Microphone,
12 First virtual point,
22 second virtual point,
24 third virtual point,
20 speakers,
30 storage unit,
40 control unit,
50 Hard sphere.

Claims (5)

A rigid body having a plurality of first virtual point, a plurality of second virtual point which is arranged three-dimensionally spaced a predetermined distance from the rigid, virtually the, one of the first virtual point and the second virtual point A first step of simulating a transfer characteristic of sound from the sound source to the receiving sound source using a transfer function, with the sound source generating sound and the other as a sound receiving sound source for receiving sound;
Source wherein a rigid, virtually and a plurality of third virtual point which is arranged on the same plane with a predetermined distance away from the rigid, one of the first virtual point and the third virtual point, which generates a sound A second step of simulating the transfer characteristic of sound from the sound source to the receiving sound source using a transfer function, with the other as a sound receiving sound source for receiving sound;
A speaker having a plurality of sound sources arranged in the same positional relationship as the first virtual point of the rigid body, and a microphone receiving sound from the speaker in the same posture as the plurality of third virtual points with respect to the rigid body , A third step of preparing a space free from obstacles between at least the speaker and the microphone, receiving sound generated from the speaker by the microphone, and detecting a transmission characteristic of the sound from the speaker; When,
A fourth step of calculating a correction value for correcting the transfer characteristic simulated in the second step so as to match the transfer characteristic detected in the third step;
Based on the correction value calculated in the fourth step , the fifth step of correcting the sound transfer characteristic calculated in the first step to generate a sound insulation degree measurement transfer characteristic;
A transmission characteristic generation method for measuring sound insulation, characterized by comprising: In the first step, the plurality of second virtual points are arranged at equal solid angles from the rigid body,
2. The transfer characteristic generation method for sound insulation degree measurement according to claim 1, wherein, in the second step, the plurality of third virtual points are arranged equiangularly on the same plane. A speaker having a plurality of sound sources;
A microphone that receives sound from the speaker and measures an acoustic level;
A control unit for controlling the speaker and the microphone and simulating sound transmission characteristics;
The controller is
A rigid body having a plurality of first virtual point, a plurality of second virtual point which is arranged three-dimensionally spaced a predetermined distance from the rigid, virtually the, one of the first virtual point and the second virtual point A sound source that generates sound, and the other as a sound receiving sound source that receives sound, and simulates the transfer characteristics of sound from the sound source to the receiving sound source using a transfer function,
Source wherein a rigid, virtually and a plurality of third virtual point which is arranged on the same plane with a predetermined distance away from the rigid, one of the first virtual point and the third virtual point, which generates a sound And, on the other hand, as a sound receiving sound source that receives sound, the transfer characteristic of sound from the sound source to the sound receiving sound source is simulated using a transfer function,
The sound from the speaker by the microphone arranged in the same posture as the plurality of third virtual points with respect to the rigid body in a state where the plurality of sound sources of the speaker are arranged in the same positional relationship as the first virtual point of the rigid body. , Detect the transmission characteristics of the sound from the speaker,
To match the detected the transmission characteristic, calculates a correction value for correcting the simulated transfer characteristics between the third imaginary point and the first virtual point,
Based on the calculated correction value, the first to correct the transfer characteristic of the simulated resulting sound between the virtual point and the second virtual point, generating a sound insulation measurement for transmission characteristic A characteristic transfer characteristic generator for measuring sound insulation. About the speaker and microphone according to claim 1 installed in a measurement environment, a measurement step of receiving sound from the speaker by the microphone and measuring a sound reception level;
And the positional relationship between the speaker and the microphone, and sound insulation measurement for transmission characteristics of claim 1, on the basis, the are received sound by a microphone when there are no obstructions between the speaker and the microphone A calculation step of calculating a virtual sound reception level;
A sound receiving level measured in said measuring step, a virtual sound receiving level calculated in the calculating step, on the basis of a sound insulation measurement step of calculating the sound insulation degree,
A sound insulation degree measuring method comprising: A speaker having a plurality of sound sources;
A microphone that receives sound from the speaker and measures an acoustic level;
And the positional relationship between the speaker and the microphone, and sound insulation measurement for transfer characteristics according to claim 1, based on the the sound receiving microphone when there is no obstacle between the speaker and the microphone calculating a virtual sound receiving level, and calculated the virtual sound receiving level, a sound level measured by the microphone, on the basis, and a control unit for calculating the sound insulation degree,
A sound insulation degree measuring device comprising:

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