WO2011083610A1

WO2011083610A1 - Acoustic characteristic adjuster for vehicle

Info

Publication number: WO2011083610A1
Application number: PCT/JP2010/068747
Authority: WO
Inventors: 裕喜田中
Original assignee: クラリオン株式会社
Priority date: 2010-01-05
Filing date: 2010-10-22
Publication date: 2011-07-14

Abstract

The acoustic characteristic within a vehicle is adjusted by easily measuring the frequency characteristic within the vehicle without having to install special external connecting equipment for measuring the frequency characteristic. An acoustic characteristic adjuster (1) for a vehicle is provided with: an evaluation sound signal generating unit (6) which can generate a plurality of evaluation sound signals in a predetermined bandwidth by changing the frequency; an evaluation sound signal outputting unit (5) which outputs the generated plurality of evaluation sound signals as evaluation sound to the interior of the vehicle through a speaker (3); a frequency characteristic measuring unit (7) which measures the frequency characteristic within the vehicle on the basis of the evaluation sound collected by means of a microphone (2); an acoustic filter generating unit (8) which generates an acoustic filter which exerts an effect of eliminating the acoustic characteristic within the vehicle and rendering the acoustic characteristic flat by obtaining the inverse characteristic of the measured frequency characteristic; and an acoustic filter application unit (8) which applies the acoustic filter to the acoustic signal which is outputted to the interior of the vehicle through the speaker (3).

Description

Vehicle acoustic characteristic adjusting device

The present invention relates to a vehicle acoustic characteristic adjusting device, and more particularly, to output an evaluation sound into a vehicle interior, determine the frequency characteristic in the vehicle interior by measuring the output evaluation sound, and use the obtained frequency characteristic. The present invention relates to an acoustic characteristic adjusting device for a vehicle that can adjust an acoustic effect in a vehicle interior.

Conventionally, after recording (measuring) the sound field characteristics of a specific space (original sound field space) such as a listening room or a concert hall, it is a space different from that space. A sound field reproduction method that virtually reproduces the measured sound field characteristics of the original sound field in a space to be reproduced (reproduced sound field space) has been proposed (for example, see Patent Document 1).

In order to reproduce the acoustic characteristics of the original sound field space in the reproduced sound field space, the frequency characteristics in the original sound field space and the frequency characteristics in the reproduced sound field space are obtained, and the reproduced sound field is compared with the frequency characteristics in the original sound field space. An acoustic filter that adds the acoustic characteristics of the original sound field space after canceling the influence of the frequency characteristics in the reproduced sound field space (by flattening the frequency characteristics) by adding the inverse characteristics of the frequency characteristics in the space. Generate. When music is output in the reproduced sound field, the sound effect in the original sound field space can be reproduced in the reproduced sound field space by outputting the music by applying the generated acoustic filter. Become.

By the way, when driving a car, the driver often listens to music in the passenger compartment. In particular, since the passenger compartment is a closed space, there are many demands for reproducing the acoustic effect of the concert hall as described above in the passenger compartment. In order to reproduce the acoustic effect of a concert hall or the like in the passenger compartment, it is necessary to obtain the inverse characteristic of the frequency characteristic in the passenger compartment in order to cancel the acoustic characteristics in the passenger compartment.

For this reason, it is necessary to determine the frequency characteristics in the vehicle interior, but the frequency characteristics in the vehicle interior have different characteristics for each vehicle type, so that it is necessary to determine the frequency characteristics individually for each vehicle type. was there. For example, when installing an in-vehicle audio device in a plurality of vehicles of different vehicle types, an optimal acoustic filter is generated for each vehicle type by obtaining the frequency characteristics in the vehicle interior for each vehicle type and output from the in-vehicle audio device. Therefore, it is not easy to reproduce an effective acoustic effect in different vehicle types.

Considering the difference in frequency characteristics for each vehicle type, by selecting the vehicle manufacturer name, vehicle type, grade, etc., the sound optimized for each vehicle type using the frequency characteristics measured for each vehicle type in advance. There has been proposed an apparatus that reads out a filter and reproduces an acoustic environment such as a concert hall using the read out acoustic filter (see, for example, Patent Document 2).

By performing acoustic correction of the acoustic signal using the acoustic filter optimized for each vehicle model in this way, it is possible to construct an optimal acoustic environment in each vehicle compartment considering various vehicle environment differences. It becomes.

Japanese Patent Laid-Open No. 2005-249989 JP 2003-153400 A

However, even if the same model and grade of the same manufacturer, if a stuffed animal is placed in the passenger compartment or if a curtain is installed near the window, it will be affected by the sound absorption / reflection sound caused by the stuffed animal or the curtain. In some cases, the frequency characteristic in the passenger compartment is different from the frequency characteristic measured in advance for each vehicle type. Furthermore, the frequency characteristics may change even in the same car depending on the seating height of the listener, the number of passengers, the presence or absence of a child seat, and the like.

Therefore, even if acoustic processing is performed using an acoustic filter prepared in advance for each vehicle type, the acoustic characteristics in the passenger compartment are effectively improved by the inverse characteristics of the frequency characteristics measured in advance due to changes in the frequency characteristics due to the effects of stuffed animals. Cannot be made flat, and there is a problem that an optimal acoustic environment may not be reproduced in the passenger compartment.

On the other hand, the frequency characteristics of the passenger compartment are measured individually, and the acoustic characteristics in the passenger compartment are flattened for each vehicle by using the inverse characteristics of the measured frequency characteristics to create an acoustic filter suitable for the passenger compartment environment. However, there is a problem that it is not easy to actually measure the frequency characteristics in the passenger compartment for each vehicle.

More specifically, when measuring frequency characteristics for each vehicle, a predetermined evaluation sound (for example, an impulse sound) is output to a general vehicle-mounted audio device, and the sound output from each speaker is output. It was necessary to install externally connected equipment for collecting and acquiring (impulse response) and measuring and calculating frequency characteristics. However, since it is necessary to attach and detach the externally connected device to / from the in-vehicle audio device only when measuring the frequency characteristic, the burden of attaching / detaching the externally connected device is generated, and the frequency characteristic is easily measured There was a problem that it was difficult.

The present invention has been made in view of the above problems, and without installing a special external connection device or the like for measuring the frequency characteristics, the frequency characteristics in the vehicle interior can be easily measured to obtain the acoustic characteristics in the vehicle interior. It is an object of the present invention to provide a vehicle acoustic characteristic adjusting device that can be adjusted.

In order to solve the above-mentioned problem, a vehicle acoustic characteristic adjusting device according to the present invention includes a microphone installed in a location near the ear position of a listener in a vehicle interior, a speaker installed in the vehicle interior, An evaluation sound signal generation unit capable of generating a plurality of evaluation sound signals in a predetermined bandwidth by changing the frequency, and the plurality of evaluation sound signals generated by the evaluation sound signal generation unit as the evaluation sound An evaluation sound signal output unit that outputs the sound from the speaker to the vehicle interior, a frequency characteristic measurement unit that measures frequency characteristics of the vehicle interior in the predetermined bandwidth based on the evaluation sound collected by the microphone, and An acoustic filter for obtaining an acoustic filter having an effect of canceling the acoustic characteristic in the passenger compartment and flattening it by obtaining an inverse characteristic of the frequency characteristic measured by the frequency characteristic measuring unit. A data creation unit, an acoustic filter created by the acoustic filter generation unit, characterized in that it comprises an acoustic filter applying unit to apply an acoustic signal to be output to the passenger compartment through the speaker.

As described above, in the vehicle acoustic characteristic adjusting device according to the present invention, the evaluation sound signal generation unit capable of generating a plurality of evaluation sound signals, and the evaluation sound signals are output as evaluation sounds from the speakers to the vehicle interior. Since the evaluation sound signal output unit is provided in advance, it is possible to output the evaluation sound signal from the speaker whenever necessary. Further, since the vehicle acoustic characteristic adjusting device is provided with a frequency characteristic measuring unit that measures the frequency characteristic in the vehicle interior based on the collected evaluation sound, the frequency is always corresponding to the output of the evaluation sound signal. It becomes possible to measure the characteristics. Therefore, in the vehicle acoustic characteristic adjusting device, it is not necessary to install an external connection device or the like for generating a predetermined evaluation sound signal and measuring and calculating the frequency characteristic based on the generated evaluation sound signal.

In addition, in the vehicle acoustic characteristic adjustment device, the frequency characteristic measurement unit can measure the frequency characteristic at any time without installing an external connection device. Based on the measured frequency characteristic, the acoustic filter creation unit can always perform the reverse characteristic. Therefore, the acoustic filter can be applied to the acoustic signal by the acoustic filter application unit, so that the acoustic characteristics in the vehicle compartment can be canceled and flattened easily and quickly at any time.

According to the vehicle acoustic characteristic adjusting device of the present invention, a predetermined evaluation sound signal is generated, and an external connection device or the like for measuring and calculating the frequency characteristic based on the generated evaluation sound signal is not installed. It becomes possible to measure the frequency characteristics in the passenger compartment.

Moreover, in the vehicle acoustic characteristic adjusting device according to the present invention, the frequency characteristic can be measured at any time without installing an external connection device, and an acoustic filter is created at any time based on the measured frequency characteristic. Therefore, it is possible to cancel the acoustic characteristics in the passenger compartment easily and quickly and make it flat.

It is the block diagram which showed schematic structure of the vehicle-mounted audio apparatus which concerns on this Embodiment. (A) shows an example of the frequency characteristic of the vehicle interior measured by the acoustic detection unit according to the present embodiment, (b) shows the inverse characteristic of the frequency characteristic shown in (a), (c) These are the figures which showed the state which canceled the acoustic characteristic in the vehicle interior and became flat by applying the reverse characteristic shown to (b) with respect to the frequency characteristic shown to (a).

Hereinafter, an in-vehicle audio apparatus including the vehicle acoustic characteristic adjusting apparatus according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of an in-vehicle audio apparatus according to an embodiment of the present invention. The in-vehicle audio apparatus 1 includes a microphone 2, a speaker 3, a sound source unit 4, an acoustic adjustment unit (evaluation sound signal output unit) 5, a signal generation unit (evaluation sound signal generation unit) 6, and an acoustic detection unit (frequency characteristics). A measurement unit) 7 and an acoustic processing unit (acoustic filter creation unit, acoustic filter application unit) 8.

The microphone 2 is installed in the vicinity of the listener's ear position where the acoustic effect can be most effectively enjoyed in the passenger compartment. Generally, it is often installed at a location near the listener's ear position in the driver's seat. Since the driver (driver) usually sits in the driver's seat, it is considered optimal to measure the acoustic characteristics in the passenger compartment based on the driver's seat where there will always be a person. Because it is.

In FIG. 1, only one microphone 2 is provided for convenience, but in reality, the microphones 2 are installed at two locations near the right ear position and near the left ear position. By installing two or more microphones 2 in the vicinity of the left and right ear positions in this way, it is possible to measure frequency characteristics in consideration of the difference in acoustic characteristics between the left and right ear positions.

Speakers 3 are installed at predetermined positions in the vehicle interior, for example, left and right front doors, left and right rear doors, left and right first pillar portions, and the like. Moreover, you may install a woofer etc. in a luggage compartment space etc. as needed. By installing a plurality of speakers 3 in this way, a powerful acoustic environment can be realized. In addition, the speaker 3 may be divided into a high-frequency speaker, a mid-range speaker, a low-frequency speaker, and the like for each band that can be output, and each of the plurality of speakers 3 It may be a high performance speaker 3 capable of outputting a wide band acoustic signal. Whatever the configuration, if a sound signal can be output in a balanced manner from the low range to the high range as a whole, a suitable acoustic environment can be reproduced.

It should be noted that in-vehicle audio apparatus 1 according to the present embodiment uses a speaker capable of outputting an acoustic signal in a band of at least 20 Hz to 20 kHz as a whole. Further, in FIG. 1, only one speaker 3 is shown for convenience, but the number of speakers 3 may be one or two or more. Etc. are not limited for each car.

The sound source unit 4 has a role of outputting an acoustic signal to be output from the speaker 3 of the in-vehicle audio device 1 as a sound source. Specifically, the sound source unit 4 is a sound source of a CD player, an MD player, or a radio, for example, and can output an acoustic signal suitable for each sound source, and an acoustic signal acquired via an external input terminal It is comprised by the apparatus etc. which can output. The acoustic signal output from the sound source unit 4 is output to the acoustic adjustment unit 5.

The acoustic adjustment unit 5 has a role of performing various acoustic adjustments on the acoustic signal output from the sound source unit 4. For example, the volume of the sound signal output from the speaker 3 is adjusted according to the operation of an operation button (not shown), or the sound signal output from the speaker 3 is adjusted (the sound localization balance is adjusted to the left and right and back and forth). ) And temporarily reduce the volume to a minimum level (so-called mute processing).

In addition, the sound adjustment unit 5 can perform various operations such as an acoustic effect such as listening to a sound signal in a concert hall according to an operation of an operation button, or an acoustic effect that makes a vocal sound appear. It is possible to add an acoustic effect. Furthermore, a signal generator 6 and a sound detector 7 are connected to the sound adjuster 5.

The signal generator 6 has a role of outputting a sine wave signal indicating various frequencies from 20 Hz to 20 kHz. Specifically, the signal generator 6 can generate a plurality of different sine wave signals having any frequency of 20 Hz to 20 kHz as an evaluation acoustic signal (evaluation sound signal). Then, the plurality of evaluation sound signals generated by the signal generation unit 6 are output to the speaker 3 by the acoustic adjustment unit 5 and output to the vehicle interior as evaluation sound by the speaker 3.

The sound detection unit 7 has a role of detecting the sound signal level for each frequency in the passenger compartment based on the signal collected by the microphone 2. In the in-vehicle audio apparatus 1 according to the present embodiment, a quasi-peak detector (Quasi Peak Detector) that detects a quasi-peak value is used as the acoustic detection unit 7. By detecting the quasi-peak value with the quasi-peak value detector, it is possible to obtain acoustic characteristics in consideration of noise noise generated in the vehicle interior. Specifically, the quasi-peak value is detected with a high measured value when the duration of noise is long or high, and is detected low when the duration of noise is short and the frequency is low. . For this reason, even if driving noise of the vehicle occurs in the passenger compartment, if the frequency of occurrence is low or the duration of the noise is short, considering the characteristics that the listener does not feel annoying noise, The influence of noise in the passenger compartment can be assumed.

The acoustic processing unit 8 has a role of obtaining a reverse characteristic with respect to the frequency characteristic detected by the acoustic detection unit 7 and filtering the acoustic signal output from the acoustic adjustment unit 5. FIG. 2A shows an example of a frequency characteristic in the passenger compartment detected by the acoustic detection unit 7. When the frequency characteristic as shown in FIG. 2 (a) is detected, the acoustic processing unit 8 can cancel the frequency characteristic shown in FIG. 2 (a), that is, the frequency shown in FIG. 2 (a). A reverse characteristic of the characteristic is created as shown in FIG. Then, the acoustic processing unit 8 performs a reverse characteristic filtering process as shown in FIG. 2B on the acoustic signal output from the acoustic adjustment unit 5, as shown in FIG. 2C. It becomes possible to cancel the frequency characteristic in the passenger compartment and make it flat. In this way, the acoustic processing unit 8 performs filtering on the acoustic signal based on the inverse characteristic of the frequency characteristic measured in the passenger compartment, so that the sound output from the speaker 3 and transmitted to the listener's ear can be obtained. It is possible to prevent the acoustic effect in the passenger compartment from being reflected.

Thus, in the in-vehicle audio apparatus 1 according to the present embodiment, since the signal generating unit 6 is provided, an evaluation sound having a frequency corresponding to the output band of the speaker 3 can be obtained whenever necessary. Can be output. Furthermore, since the in-vehicle audio apparatus 1 is provided with the acoustic detection unit 7 that detects the frequency characteristics in the vehicle interior based on the signal collected by the microphone 2, it always corresponds to the output of the evaluation sound signal. It becomes possible to measure frequency characteristics.

Therefore, in the in-vehicle audio apparatus 1, it is not necessary to install an external connection device or the like for generating a predetermined evaluation sound signal and measuring and calculating the frequency characteristic based on the generated evaluation sound signal. Further, in the in-vehicle audio apparatus 1, the frequency characteristic can be detected by the acoustic detection unit 7 at any time without installing an external connection device, and the inverse characteristic is always performed by the acoustic processing unit 8 based on the detected frequency characteristic. Since it can be generated and filtered, the reverse characteristic in the passenger compartment can be obtained simply and quickly and reflected in the acoustic signal output from the speaker 3.

Furthermore, since the frequency characteristics in the vehicle compartment can be obtained simply and quickly, it is not necessary to record a plurality of acoustic filters based on the frequency characteristics measured in advance for each vehicle type as in the case of a conventional in-vehicle audio apparatus. . In addition, because the frequency characteristics of the passenger compartment can be easily and quickly determined at any time for each vehicle type, even in environments where stuffed animals or curtains are installed in the passenger compartment, the sound absorption / reflection conditions caused by the installation of stuffed animals etc. Frequency characteristics corresponding to changes can be obtained, and even when there are changes in the number of passengers, frequency characteristics suitable for the situation can be obtained easily and quickly each time. It becomes.

As described above, the in-vehicle audio apparatus 1 according to the present embodiment is shown and the vehicle acoustic characteristic adjusting apparatus according to the present invention has been described. However, the vehicle acoustic characteristic adjusting apparatus according to the present invention has It is not limited to the on-vehicle audio apparatus 1 shown. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

1 ... In-vehicle audio device (vehicle acoustic characteristic adjusting device)
2 ... Microphone 3 ... Speaker 4 ... Sound source unit 5 ... Sound adjustment unit (evaluation sound signal output unit)
6 ... Signal generator (evaluation sound signal generator)
7: Sound detection unit (frequency characteristic measurement unit)
8: Acoustic processing unit (acoustic filter creation unit, acoustic filter application unit)

Claims

A microphone installed near the listener's ear position in the passenger compartment;
A speaker installed in the vehicle interior;
An evaluation sound signal generation unit capable of generating a plurality of evaluation sound signals in a predetermined bandwidth by changing the frequency; and
An evaluation sound signal output unit that outputs a plurality of evaluation sound signals generated by the evaluation sound signal generation unit from the speaker to the vehicle interior as an evaluation sound;
Based on the evaluation sound collected by the microphone, a frequency characteristic measuring unit that measures frequency characteristics in the vehicle interior in the predetermined bandwidth;
An acoustic filter creation unit for creating an acoustic filter having an effect of canceling the acoustic characteristic in the vehicle interior and obtaining a flattened result by obtaining an inverse characteristic of the frequency characteristic measured by the frequency characteristic measurement unit;
An acoustic filter adjustment device for a vehicle, comprising: an acoustic filter application unit that applies the acoustic filter created by the acoustic filter creation unit to an acoustic signal output to the vehicle interior via the speaker.