JPH09258750A - Sound insulating simulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize sound insulating simulation of high accuracy by taking account of background noise caused by indoor air-conditioning equipment. SOLUTION: A voice signal to be an object of sound insulation evaluation is outputted from a sound source recording reproducing device 44, provided with a sound insulation characteristic by a digital filter and reproduced by a speaker or a headphone. A noise signal corresponding to background noise caused by indoor air-conditioning equipment is generated from background noise source 58, and four channel noise signals different in phase are generated by a phase shifter 60, made astatic and reproduced by the speaker or headphone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when designing a sound insulation structure in a soundproof room such as a listening room or a music practice room, simulates the sound insulation performance of various sound insulation structures in an electroacoustic manner so that the subject can experience it. The sound insulation simulator that can be evaluated is closer to the actual feeling in the listening room.

[0002]

2. Description of the Related Art Designing a sound insulation structure is important in designing a soundproof room such as a listening room or a music practice room. Of course, it is desirable for the soundproof room to have high sound insulation, but the higher the sound insulation, the higher the cost.
It is important to design a sound insulation structure that provides a sound insulation level that is necessary and not too high, depending on the noise level of the surrounding environment, the purpose of use, the individual subjectivity (satisfaction) of the user, and the like.

The sound insulation simulator electro-acoustically simulates the sound insulation performance of various sound insulation structures when designing the sound insulation of the sound insulation room so that the subject (user of the sound insulation room) can feel and evaluate the sound insulation performance. The sound insulation structure (wall material, structure, thickness, window structure, size, etc.) can be easily designed.

In a conventional sound insulation simulator, a sound signal corresponding to a sound insulation target is generated from a sound source device, attenuated through a filter having a characteristic equivalent to a sound insulation structure set appropriately, and reproduced by a speaker arranged in a listening room. Then, the test subject was able to experience the sound insulation performance.

[0005]

Air-conditioning equipment such as an air conditioner is often provided in a soundproof room, and the sound generated from the air-conditioning equipment becomes so-called background noise, which greatly affects the testimony of the subject. However, in the conventional sound insulation simulator, since the background noise generated in such a room is not considered, the sound insulation performance experienced by the simulation and
There was a gap between the soundproofing performance and the soundproofing performance actually felt in the soundproofing room.

The present invention solves the above-mentioned problems in the prior art so that the user can experience the soundproofing performance closer to that of an actual soundproofing room, and the soundproofing structure can be designed with higher accuracy. Is to provide.

[0007]

SUMMARY OF THE INVENTION According to the present invention, an audio signal corresponding to a sound insulation evaluation target is generated from a sound source device and is attenuated by passing through a filter having a characteristic corresponding to a sound insulation structure set as appropriate to a speaker or headphones. And at the same time, a noise signal corresponding to background noise generated by an air conditioner or the like generated indoors is generated from a noise generation source and is reproduced by a speaker or headphones without passing through the filter.

According to this, it is possible to simulate the background noise generated by the air conditioning equipment or the like generated in the soundproof room (listening room, music practice room, etc.) to be designed, and then to experience the sound insulation performance against external noise. It is possible to experience the soundproofing performance closer to that of an actual soundproofing room, and it is possible to evaluate and design the soundproofing structure with higher accuracy.

It should be noted that by reproducing a voice signal corresponding to the noise of the sound insulation evaluation that is generated outdoors by a stereo signal, and by phase-shifting and reproducing the noise signal corresponding to the background noise generated indoors by multi-channel reproduction. , The noise from the outside of the sound insulation evaluation target is reproduced realistically, and the background noise generated indoors is avoided to be localized in a specific place (that is, non-localized) and reproduced with the characteristic of background noise. And a more realistic simulation is achieved.

Further, the background noise generated by the air conditioning equipment in the room is generally caused by NC (Noise Criterion).
Since the noise signal has a frequency characteristic close to a curve, the noise signal having a frequency characteristic substantially along the NC curve can generate a noise signal closer to the background noise generated in the room.

[0011]

Embodiments of the present invention will be described below. First, FIG. 2 shows an outline of the sound insulation simulation in this embodiment. In this embodiment, FIG.
As shown in (a), two rooms 12, 1 blocked by a wall 13
4 has a sound source 16 to be sound-insulated in one room 12, the other room 14 has an air-conditioning system 18 and a listening sound 20, and the sound-insulating performance of the wall 13 that blocks the two rooms 12 and 14 is electroacoustic. It is supposed to be simulated.

FIG. 2 (b) is a diagram showing the overall structure of the sound insulation simulator 10 for simulating the state of FIG. 2 (a). In the listening room 22 where the subject 20 is located, the left and right two-channel main speakers 24 and 26, the front left and right two channels, and the rear left and right two channels are background noise speakers 28 and 3.
0, 32, 34 are installed.

From the sound insulation simulator main body 11, FIG.
The main signal simulating the sound of the sound source 16 to be evaluated for sound insulation shown in FIG.
A background noise signal simulating the background noise due to is output. The main signal is reproduced by the main speakers 24 and 26 via the power amplifier 36. The background noise signal is transmitted via the power amplifier 38 to the background noise speakers 28, 30, 32, 34.
Will be played back.

When simulating in a place where a soundproof room is installed, or in a place where the background noise level is high, as shown in FIG.
A signal obtained by mixing the main signal and the background noise signal is output from the simulator body 10, and the headphones 40 perform a trial listening.

The system configuration of the sound insulation simulator main body 11 is shown in FIG. By accommodating the entire system configuration in a carrying case such as an attache case and making it portable, it is possible to bring it to a site where a soundproof room is to be created and perform a simulation.

In FIG. 1, the control personal computer 42 controls each part of the apparatus based on the operation of the keyboard 43 by the operator to execute the simulation. Sound source recording / playback device 4
4 is MD (Mini Disk), DCC (Digit)
al Compact Cassette), DAT (Dig
It is composed of a digital recording / reproducing apparatus such as an digital audio taper), and records and reproduces a sound signal of a sound insulation evaluation target by two channels.

The external input terminals 46 and 48 transmit the sound signal for sound insulation evaluation before the simulation is performed by the sound source recording / reproducing apparatus 4.
When recording to 4, input the recording signal with the microphone input or line input. Further, during reproduction (during simulation execution), an external input signal is input by a microphone input or a line input in order to mix the external input signal with the signal reproduced from the sound source recording / reproducing device 44 as necessary.

The switch 50 switches between input of a recording signal and output of a reproduction signal of the sound source recording / reproducing device 44. In addition, at the time of reproduction, switching between stereo reproduction and monaural reproduction (mixing of left and right channels) and switching between mixing external input with a reproduction signal are performed. The switch 52 switches whether or not significant external noise is mixed with room air-conditioning noise when necessary during simulation.

The digital filter 54 is composed of a DSP, and the sound insulation structure arbitrarily selected by the operator for the sound signal to be evaluated for sound insulation reproduced from the sound source recording / reproducing device 44 (or the external input is mixed with this). FIR filter characteristics corresponding to the sound insulation characteristics of are added. still,
The DSP forming the digital filter 54 also has a function of imparting a sound field effect (reverberation sound generation). The storage device (hard disk or the like) 56 of the personal computer 42 accommodates a plurality of types of filter characteristic data (FIR filter coefficient data) corresponding to the sound insulation characteristics of various sound insulation structures, and stores the sound insulation structure selected by the operator. The data is read and set in the digital filter 54. The storage device 56 also stores sound insulation degree numerical data corresponding to the sound insulation characteristics, a sound insulation performance graph, a sound insulation structure diagram, and other related data (see FIG. 10) as a database.
Reverberation sound generation data is also stored in the storage device 56.

The background noise source DSP 58 produces a background noise signal corresponding to indoor air conditioning equipment such as an air conditioner, and outputs pseudo white noise after filtering it in a manner substantially equivalent to the NC curve. The phase shifter 60 phase-shifts the background noise signal to generate four-channel background noise signal whose phases are mutually shifted.

The output is a 2-channel main signal output terminal 6 for outputting a sound insulation evaluation target signal having sound insulation characteristics.
2, 64, four-channel background noise signal output terminals 66, 68, 70, 72 for outputting background noise signals, and headphone output terminals 74, 76 are provided. From the headphone output terminals 74 and 76, signals obtained by mixing the main signal and the background noise signal with the mixers 78 and 80 are output. Headphone output terminals 74 and 76 are provided in four systems.
It allows people to listen to them at the same time and evaluate jointly.

In the sound insulation simulator main body 11 of FIG. 1, when a sound signal to be evaluated for sound insulation is recorded in the sound source recording / reproducing device 44, the corresponding sound signal is input from the external input terminals 46 and 48 by microphone input or line input. .
This recording signal is applied to the head amplifiers 82, 8 with attenuator.
The signal is converted into a digital signal by the A / D converter 84 via the switch 3 and the switch 50, and signal processing such as frequency characteristic adjustment is performed by the digital filter 54 as necessary (pass as it is if not necessary), and D / A conversion. The analog signal is returned by the device 86, the recording level is adjusted by the attenuators 88 and 90, and the sound is recorded in the sound source recording / reproducing device 44.

When executing the simulation, the sound signal reproduced by the sound source recording / reproducing device 44 is mixed with an external input signal by the switch 50 as required, A / D converted by the A / D converter 84, and digitally converted. A filter characteristic corresponding to the sound insulation structure arbitrarily selected by the operator is given by the filter 54. The audio signal output from the digital filter 54 is converted into an analog signal by the D / A converter 86 and output from the main signal output terminals 62 and 64 via the amplifiers 92 and 94.

The background noise signal output from the background noise source 58 during the simulation is converted into an analog signal by the D / A converter 96, the external significant noise is mixed by the mixer 98 as necessary, and the phase shifter 60 is used. The signal is phase-shifted by and is output from the background noise signal output terminals 66, 68, 70, 72. Further, the main signals ch1 and ch2 and the background noise signals BGN1 and BGN2 are mixed by the mixers 78 and 80 and output from the four headphone output terminals 74 and 76 via the headphone amplifiers 100 and 102.

Here, the sound insulation simulator main body 11 of FIG.
The configuration of each part will be described. In the case of simulating sound insulation performance, the digital filter 54 tries to approximate even the audible impression, and the frequency is 5 Hz especially in the low frequency range.
It is necessary to realize a degree of resolution. Therefore, the digital filter 54 performs multi-sample rate signal processing whose conceptual configuration is shown in FIG. 3, for example. This is to divide the input signal into two bands, a high band and a low band, and lower the sample rate on the low band side to increase the resolution of the FIR filter without increasing the hardware scale. . That is, the digital filter 54 shown in FIG.
04, and a subtracter 110 via a delay adjustment delay 117 generated by the low-pass filter 104, and divides into two bands by a low-range sound-insulating filter 106 that imparts sound-insulating characteristics on the low-range side, and a high-range side. The high-frequency sound-insulating filter 108 that imparts sound-insulating characteristics is filtered by changing the sampling frequency, and the low-pass filter 11 is used for the low-frequency side.
1 through the low pass filter 111 on the high frequency side.
The delay 119 delays the output corresponding to the delay generated in step 119, and the mixer 115 mixes the signals in both bands and outputs the mixed signals. The low frequency sound insulation filter 106 filters at a sample rate of, for example, 1/32 of the high frequency sound insulation filter 108. The low-frequency sound-insulating filter 106 and the high-frequency sound-insulating filter 108 are set with the filter coefficients read from the memory 56 (FIG. 1), and convolute the input audio signal and output it.

According to this, in order to cover a band up to, for example, 20 kHz and to provide a frequency resolution of about 5 Hz, a normal FIR filter has 800 taps.
While 0 or more is required, in the digital filter 54 of FIG. 3, if the low-pass filter 104 is set to cut off 689 Hz or more and the sample route on the low frequency side is set to 1/32 on the high frequency side, A low-frequency resolution of 5.38 Hz is realized with 256 taps.

Background noise source DSP 58 and phase shifter 60
FIG. 4 shows the internal structure of the. The M-sequence signal generator 112 is
For example, as shown in FIG. 5, the shift register 114 of n stages (for example, 23 stages) and the exclusive OR circuit 116 are combined. As an initial state, at least one stage or more of the shift register 114 is set to "1" and sequentially shifted in accordance with the clock generated from the clock generation circuit 118 (FIG. 4) to generate a wide band pseudo random signal ( (Pseudo white noise) can be generated.

The pseudo white noise signal output from the M-sequence signal generator 112 is input to the filter bank 120. The filter bank 120 is composed of a 9-band IIR filter and extracts a signal for each octave band from a wide band pseudo white noise signal. The level of the signal in each band is adjusted by the corresponding attenuator 122 (equalizing means) to obtain a desired frequency characteristic. The data table 124 (memory) accommodates various data of the frequency characteristics along the NC curve and other arbitrary frequency characteristics as the characteristic data of the attenuator 122, and the personal computer 42 based on the operation of the keyboard 43 by the operator. Command, the arbitrary characteristics are read and set in the attenuator 122. As a result, the attenuator 122 outputs a broadband noise signal having a frequency characteristic substantially along the NC curve or any other frequency characteristic.

The output of the attenuator 122 is combined and output by the mixing and output level adjuster 126. FIG. 6 shows an example of the measured value of the background noise generated from the indoor air conditioning equipment (air conditioner), which shows the characteristics substantially along the NC curve in the band above about 250 Hz.
In 24, for example, the frequency characteristic data substantially along the NC curve is stored.

The case where the noise generated from the noise source 112 is white noise has been described above. However, when another type of broadband noise source is used, the attenuator 122 is used according to the frequency characteristic of the noise itself.
By adjusting (equalizing means), a noise signal having a frequency characteristic or an arbitrary frequency characteristic substantially along the NC curve is created.

In FIG. 4, the phase shifter 60 includes a buffer amplifier 128 and analog type phase shift circuits 130 and 1.
The background noise signal is composed of 32 and 134 and has four channels with mutually shifted phases. The phase characteristic of each output is shown in FIG. 2 channels B out of 4 channels output
GN1 and BGN2 are mixed with the main signal and used together for headphone output. By reproducing a plurality of background noises whose phases are shifted from each other from different positions, it is possible to eliminate the localization of the background noises and to reproduce the background noises with a feeling of background noises.

The operation procedure of the simulation by the sound insulation simulator 10 having the above configuration will be described with reference to FIG. First, a reference reproduction level is set prior to recording a sound insulation evaluation target signal (S1). That is, the conditions of the reproduction system equipment (power amplifiers 36, 38, main speakers 24, 26, etc. of FIG. 2) and the listening room 22 are fixed, and a reference sound source (pink noise, etc.) of a predetermined signal level is applied to this reproduction system. When input, this reference sound source is reproduced from the speaker at a predetermined sound pressure level (for example, when the reproduced sound pressure level setting display is 100 dB, the sound pressure level actually reproduced from the speaker is 100 dB). ), Adjust the output signal level of the playback system.

Then, the average level (OA value) of the sound source signal to be sound-insulated is measured, and the sound source recording / reproducing apparatus 44 is reproduced so that it is reproduced at a signal level equal to the signal level of the reference sound source. Adjust the input signal level of (S2) and record the sound source signal for sound insulation (S2)
3). When the sound source recording / reproducing apparatus 44 is reproduced by recording the sound insulation target sound source signal in this way, the sound insulation target sound source is reproduced from the speaker at the predetermined sound pressure level when the sound insulation level is set to 0 dB. It will be. Also, if you change the playback level setting of the sound insulation target sound source during playback,
When the sound insulation level is 0 dB, the sound insulation target sound source is always reproduced from the speaker at the sound pressure level at which the reproduction level setting is displayed.

When the recording is completed, the simulation is performed.
When simulating, first, simulation parameters are set (S4). A display screen of the personal computer 42 when setting the simulation parameters is shown in FIG. The simulation parameters are as follows.

(A) Reproduction system: Speaker reproduction or headphone reproduction is selected. (B) Playback pattern Main STEREO, Main MONO, BGN
3 reproduction patterns can be selected. Mai
In n STEREO, the signal L + ch1 obtained by combining the L channel of the sound source recording / reproducing device 44 and the externally input ch1 is c.
A signal R + ch2 output from the main output terminal 62 of h1 and combining the R channel of the sound source recording / reproducing device 44 and ch2 of the external input is output from the main output terminal 64 of ch2, and the background noise signal output terminals 66, 68, 70, A background noise signal from the background noise source DSP 58 is output from 72.
In Main MONO, L + R of sound source recording / playback device 44
Is output from the ch1 main output terminal 62, the external input signal ch1 + ch2 is output from the ch2 main output terminal 64, and the background noise signal output terminals 66, 68, 70, 72 are output.
Outputs a background noise signal from the background noise source DSP 58. In BGN, the main output terminal 62 outputs L of the sound source recording / playback apparatus 44, the main output terminal 64 outputs R of the sound source recording / playback apparatus 44, and the background noise signal output terminals 66, 68, 70, 72. A signal obtained by mixing the background noise from the background noise source DSP 58 and the external input signals ch1 and ch2 (that is, the switch 52 is turned on at this time) is output. By using BGN, it is possible to simulate a state in which the noise from the next room is mixed with the noise from the outside.

(C) Sound insulation The sound insulation is set as a sound insulation characteristic by a D grade or an actual measurement value. The sound insulation level can be set for each channel. Simultaneous reproduction of different sound insulation levels makes it possible to reproduce sound insulation defects. (D) Background noise Set whether or not background noise is added and the characteristics (NC value etc.) when it is added. Note that the gain of the entire background noise system is adjusted in advance so that the background noise is reproduced with the set characteristics (NC value, etc.) when the simulation is executed. (E) Reproduction level Set the reproduction level of the main signal.

When the simulation parameters are set as described above, various data corresponding to the set sound insulation level are read from the storage device 56 and displayed on the display screen of the personal computer 42. The display image is shown in FIG. Here, the sound insulation numerical value data 134, the sound insulation performance graph (overwritten on the D grade curve) 136, the sound insulation structure diagram 138, the related data 140, and the like are displayed. Further, the sound insulation filter coefficient data is read from the storage device 56 and set in the digital filter 54 (S6). As a result, the simulation becomes possible, and the simulation is started by setting the sound source recording / reproducing device 44 in the reproducing state (S7).

During the simulation, the sound insulation evaluation target signal is at the sound pressure level obtained by multiplying the reproduction level (sound pressure level) set in (e) by the attenuation corresponding to the sound insulation degree set in (c). The background noise is reproduced and the background noise is reproduced at the sound pressure level corresponding to the characteristic set in (d) above. Then, the sound insulation performance is evaluated (S8), and if it is satisfactory, the sound insulation structure is determined (S9, S10). If it is not satisfied, the sound insulation is set again and the simulation is repeated (S11).

[0039]

As described above, according to the present invention,
It is possible to perform a highly accurate sound insulation simulation considering the influence of background noise of indoor air conditioning.

[Brief description of drawings]

1 is a diagram showing an embodiment of the present invention, and FIG.
It is a block diagram which shows the system configuration of the sound insulation simulator main body 11 of (b) and (c).

FIG. 2 is a schematic diagram showing an embodiment of the present invention.

3 is a block diagram showing a conceptual configuration of a digital filter 54 in FIG.

4 is a block diagram showing configurations of a background noise source DSP 58 and a phase shifter 60 shown in FIG.

5 is a diagram showing a configuration example of an M-sequence signal generator 112 of FIG.

FIG. 6 is a diagram showing an example of indoor air conditioning noise.

7 is a characteristic diagram of the phase shifter 60 of FIG.

FIG. 8 is a flowchart showing a procedure of simulation by the sound insulation simulator 10 of FIG.

9 is a diagram showing a display on a personal computer display screen in step S4 of FIG.

10 is a diagram showing a display on a personal computer display screen in step S5 of FIG.

[Explanation of symbols]

10 Sound Insulation Simulator 11 Sound Insulation Simulator Main Body 13 Wall (Sound Insulation Structure) 16 Sound Source (Noise Source for Sound Insulation Evaluation Outside the Room) 18 Air Conditioning Facility (Background Noise Source Inside the Room) 24, 26, 28, 30, 32, 34 Speaker 40 Headphones 43 Keyboard (filter characteristic data selection means) 44 Sound source recording / reproducing device (sound insulation evaluation target voice signal generating means) 54 Digital filter 56 Memory (sound insulation characteristic memory) 58 Background noise source DSP (noise signal generating means) 60 Phase shifter ( Phase shift means)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location G06F 15/60 612A (72) Inventor Satoshi Kobayashi 10-1 Nakazawa-machi, Hamamatsu-shi, Shizuoka Yamaha Stock Company Within

Claims (3)

[Claims] 1. A sound insulation characteristic memory holding a plurality of kinds of filter characteristic data corresponding to sound insulation characteristics of various sound insulation structures, and an operator's selection operation from the plurality of kinds of filter characteristic data stored in the sound insulation characteristic memory. Filter characteristic data selection means for reading the filter characteristic data that is arbitrarily selected by, and generating a sound signal for sound insulation evaluation that generates a sound signal for sound insulation evaluation that corresponds to the noise generated from the noise source that is outside the room. Means, a digital filter which is set to the filter characteristic read from the sound insulation characteristic memory, and which outputs the sound insulation evaluation target audio signal by applying a corresponding filter characteristic, and a digital filter generated from a background noise source existing in the room. Noise signal generating means for generating a noise signal corresponding to background noise, and the filter characteristic is added Sound evaluated audio signals and sound insulation simulator made by and a speaker or headphones the filter characteristic reproduces the noise signal has not been granted. 2. A sound insulation characteristic memory holding a plurality of kinds of filter characteristic data corresponding to sound insulation characteristics of various sound insulation structures, and an operator's selection operation from the plurality of kinds of filter characteristic data stored in the sound insulation characteristic memory. Filter characteristic data selection means for reading out the filter characteristic data arbitrarily selected by the sound insulation evaluation target for sound insulation evaluation target corresponding to the noise generated from the noise source existing outside the room. Audio signal generating means, a digital filter which is set to the filter characteristic read from the sound insulation characteristic memory, and which outputs the sound insulation evaluation target audio signal with the corresponding filter characteristic, and the background noise existing in the room Noise signal generating means for generating a noise signal corresponding to background noise generated from the source, and the generated noise signal. Phase shifting means for shifting the phase of the signal to generate noise signals of a plurality of channels whose phases are shifted from each other, the sound insulation evaluation target audio signal to which the filter characteristic is given, and the filter characteristic is not given and A sound insulation simulator comprising a speaker or headphones for reproducing the phase-shifted noise signals of the plurality of channels. 3. The sound insulation simulator according to claim 1, wherein the noise signal has a frequency characteristic substantially along an NC curve.