JP2003244785A - Sound volume correction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound volume correction apparatus capable of reducing an audible sense of incongruity. <P>SOLUTION: The sound volume correction apparatus 100 includes: a microphone 140 placed at a prescribed position in an acoustic space; an amplifier 120 for amplifying a received audio sound at a prescribed gain; and a control section 130 for adjusting the gain of the amplifier 120 in response to a level of surrounding noise detected by the microphone 140. The control section 130 calculates an integrated stimulus amount on the basis of a level of surrounding noise and its consecutive time or the like so as to discriminate a degree of fatigue caused in an audible sense system and adjusts the gain by taking into account the degree of fatigue. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a volume correcting device for varying the volume of voice output from an on-vehicle audio device or the like according to ambient noise.

[0002]

2. Description of the Related Art Conventionally, there has been known a sound volume correction device which corrects an output level of an audio sound by following a fluctuation in the ambient noise level in an acoustic space where an audio sound and other ambient noise exist. . For example, if this volume correction device is applied to a vehicle equipped with an audio device, the output level of the audio sound will change according to the level fluctuations of ambient noise such as road noise and engine noise that occur as the vehicle runs. Is corrected, so that the user can listen to the audio sound without being disturbed by ambient noise.

In the conventional volume correction device as described above,
The average level of each of the audio sound and the ambient noise is calculated, and correction is performed by amplifying the audio sound with a predetermined gain based on each average level. The relationship between each average level and gain is obtained in advance based on human auditory characteristics, and is uniquely determined based on each average level of audio sound and ambient noise.

[0004]

By the way, in the above-mentioned conventional volume correction device, the extent to which the volume of the audio sound is corrected is uniquely determined based on the ambient noise, and the degree of human auditory fatigue. Did not consider.
For example, when a highway is maintained at a high level for a long time such as traveling on a highway for a long time, and then an interchange is taken on the highway, the acoustic space suddenly becomes quiet. Under such a condition that the user is aurally tired, even if the audio volume is controlled to be heard at a constant level by the above-described volume correction device, the audio is actually heard as if it is reduced. There was a problem that a sense of discomfort occurred.

FIG. 4 and FIG. 5 are schematic views of a conventional volume correction device that does not consider fatigue of the auditory system. In these figures, A indicates an amplifier gain that is actually set by using a conventional volume correction device, B indicates a gain of an audio audio sound, and C indicates a range where the ambient noise level is high. As shown in FIG. 4, when the ambient noise level rises, the amplifier gain indicated by A also rises by this rise amount, so that the level of the auditory audio sound indicated by B should always be kept constant. However, when the auditory system fatigues, it actually feels like a small sound even when listening to the same level of audio sound, so as shown in FIG.
When the ambient noise level suddenly decreases, an uncomfortable feeling that the audio level of the audio sound is lowered occurs.

The present invention was created in view of the above points, and an object of the present invention is to provide a volume correction device capable of reducing a sense of discomfort in hearing.

[0007]

In order to solve the above-mentioned problems, a volume correcting apparatus of the present invention is a sound volume correcting device installed in a predetermined position in an acoustic space, and a surrounding area collected by the sound collecting device. Fatigue determining means for determining the degree of auditory fatigue based on noise, and volume adjusting means for varying the volume of the sound to be corrected based on the degree of fatigue determined by the fatigue determining means. Since the degree of auditory fatigue is determined based on the ambient noise and the volume of the voice is changed, it is suitable even when the audio system is heavily fatigued by listening to the audio sound for a long time in an environment with a large ambient noise. It is possible to set various volume levels, and it is possible to reduce a sense of discomfort in hearing when the level of ambient noise suddenly decreases.

Further, it is desirable that the above-mentioned fatigue judging means judges the degree of fatigue based on the accumulated value of the ambient noise level and the elapsed time. The degree of fatigue of the auditory system varies greatly not only with the level of ambient noise, but also with the elapsed time in the environment of this ambient noise.
By using both of these cumulative values, the degree of fatigue can be accurately determined.

Further, the apparatus further comprises state determining means for determining the state in the acoustic space based on the difference between the actual voice output level and the level of ambient noise, and the above-mentioned volume adjusting means is the fatigue degree and state determining means. It is desirable to change the volume based on the result of the state determination according to. How much you can change the volume to eliminate discomfort in hearing,
It changes depending on the relative difference between the ambient noise level and the actual output sound level at that time, so the state in the acoustic space is judged based on this difference, and the variable amount of the volume is determined based on the judgment result. By setting, it is possible to further reduce the sense of discomfort in hearing.

Further, it is desirable that the above-mentioned correction target sound is an audio sound output from an audio device mounted on a vehicle. When the vehicle interior space is used as an acoustic space, the level of ambient noise that enters the acoustic space is large, and the level changes significantly. For example, the level of the ambient noise may suddenly decrease after listening to the audio sound for a long time under a large ambient noise, as in the case of traveling down the highway after traveling on the highway for a long time. Even in such a case, by correcting the audio sound output from the audio device mounted in the vehicle as the correction target sound, the occurrence of aural discomfort for the listening user is eliminated or reduced. It will be possible.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a volume correcting apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a volume correction device according to an embodiment. The volume correction apparatus 100 according to the present embodiment follows the level fluctuation of the ambient noise, corrects the volume of the audio sound output from various audio sources, and outputs the audio sound from the speaker 230. In the present embodiment, as the audio source, a CD (compact disc) player 200 and an MD (mini disc) player 2 mounted on a vehicle are used.
10. Consider the radio receiver 220.

As shown in FIG. 1, the volume correction device 100
Is a changeover switch 110, an amplifier 120, a control unit 13
0, a microphone 140, an operation unit 150, and a clock 160. The changeover switch 110 includes a CD player 200, an MD player 210, a radio receiver 22.
0 is connected, and an audio source that is an input source of the correction target sound is selected. The amplifier 120 is
The audio sound output from the audio source selected by the changeover switch 110 is amplified with a predetermined gain and output from the speaker 230 into the vehicle interior space.

The control unit 130 controls the operation of selecting the audio source by the changeover switch 110, and also controls the gain of the amplifier 120 to be varied based on the ambient noise level and the like. Details of the control unit 130 will be described later. The microphone 140 is installed at a predetermined position in the vehicle interior space, and collects the sound that reaches this position. The operation unit 150 includes various operation keys operated by the user, and is for inputting operation instructions by the user. In addition to the CD key 151, the MD key 152, and the radio key 153 used by the user to select and select the audio source, the various operation keys provided in the operation unit 150 may be manually adjusted by the user. An up / down key 154 used to perform the operation and an “automatic” key 155 used to instruct activation / invalidation of an automatic volume adjusting function for automatically adjusting the gain of the amplifier 120 according to the level of ambient noise and the like. include. Watch 1
60 measures the time or measures the elapsed time from a predetermined timing.

Next, the details of the control unit 130 will be described. As shown in FIG. 1, the control unit 130 includes a source selecting unit 131, a volume setting unit 132, and an ambient noise measuring unit 13.
3, vehicle interior state determination unit 134, cumulative stimulation amount update unit 13
5, an amplifier gain adjusting unit 136 is provided.

The source selection unit 131 includes a CD key 151, an MD key 152, a radio key 1 provided in the operation unit 150.
Based on the pressed state of 53, the switching state of the audio source by the changeover switch 110 is set. For example,
When the CD key 151 is pressed, the CD player 2
Control is performed to set the changeover switch 110 so that the output sound of 00 is selected.

The volume setting unit 132 is an operation unit 150.
The up / down key 154 provided on the monitor is monitored for the pressing state, and the volume adjustment value VO corresponding to the pressing state is monitored.
Set L. For example, the volume setting unit 132 sets the volume adjustment value VOL at predetermined intervals.

The ambient noise measuring unit 133 includes the microphone 1
The ambient noise in the vehicle interior space is measured based on the output of 40. The vehicle interior state determination unit 134 records the vehicle interior state at a predetermined timing, and determines the vehicle interior state transition based on the recorded content. When the amplifier gain at the time of interest is G and the ambient noise is BGN, the vehicle interior state X at that time can be expressed by X = G-BGN. The amplifier gain G is converted into a sound level collected by the microphone 140 when a certain amplifier gain is set and an audio sound is output from the speaker 230. Therefore, the state of the vehicle interior is the audio sound output at that time minus the ambient noise.

The vehicle interior state transition is a transition state of the vehicle interior state at the time of interest with reference to the vehicle interior state at the time when the automatic volume adjustment function is activated or when the volume adjustment value is changed. Is shown. When the reference vehicle interior state is X0 and the vehicle interior state at the time of interest is X, the vehicle interior state transition Y can be expressed as Y = X0−X.

The cumulative stimulus amount updating unit 135 updates the cumulative stimulus amount by accumulating the product value of the function continuation time and the ambient noise level from the time when the automatic sound volume adjusting function is activated to the point of interest. Assuming that the accumulated stimulation amount before updating is V, the function continuation time from the activation of the automatic sound volume adjusting function to the point of interest is T, and the ambient noise level is BGN, the accumulated stimulation amount after updating V ′
Can be expressed as V ′ = V + T × BGN.

The amplifier gain adjusting unit 136 updates the amplifier gain G on the basis of the vehicle interior state transition Y, the function continuation time T, and the integrated stimulation amount V. Specifically, (1) When Y = 0, G × f (T, V) is set as a new G. (2) When Y <0 and Y> 0, (G + Y) × f (T,
Let V) be the new G. Here, f (T, V) is a function of the function continuation time T and the integrated stimulus amount V, and is for adjusting the amplifier gain G based on the fatigue of the auditory system. For example, when an audio sound is heard under a large ambient noise for a long time, fatigue of the auditory system occurs. Therefore, the function f is used to adjust the variable amount of the amplifier gain G according to the degree of the fatigue. There is. Generally, the level variation of auditory voice considering the fatigue of the auditory system is a temporal threshold variation (temporal threshold variation).
Since it is known as shift: TTS), the function f may be set so as to correct this variation.

The above-described microphone 140 corresponds to sound collecting means, the cumulative stimulus amount updating section 135 corresponds to fatigue judging means, the amplifier gain adjusting section 136 corresponds to volume adjusting means, and the vehicle interior state judging section 134 corresponds to state judging means. . The volume correction apparatus 100 of this embodiment has such a configuration, and its operation will be described next.

FIG. 2 is a flow chart showing the operation procedure of the volume adjusting operation by the volume correcting apparatus 100. First, the source selection unit 131 has the CD key 15 provided in the operation unit 150.
1, the contents of the changeover of the changeover switch 110 are set in accordance with the pressed states of the MD key 152 and the radio key 153, and thereby any audio source is selected (step 100). Further, the volume setting unit 132 sets the volume adjustment value VOL according to the pressed state of the up / down key 154 (step 101).

Next, the amplifier gain adjusting section 136 determines whether or not the automatic key 155 provided in the operating section 150 is pressed to enable the automatic volume adjusting function (step 102). If the automatic key 155 is not pressed and the automatic volume adjustment function is not enabled, a negative determination is made, and then the amplifier gain adjustment unit 136 determines that the volume adjustment value set by the volume setting unit 132. The VOL is directly used as the amplifier gain G to adjust the gain of the amplifier 120 and the audio sound is output from the speaker 230 (step 103). Then step 100
Then, the operation of selecting the audio source is repeated.

Further, the automatic key 1 provided in the operation unit 150
When 55 is pressed and the volume automatic adjustment function is enabled, an affirmative determination is made in the determination of step 102 described above, and then the vehicle interior state determination unit 134 activates the volume automatic adjustment function. After that, it is determined whether or not the initialization processing has already been performed (step 104), and if it has been performed, an affirmative determination is made, and then the up / down key 154 of the operation unit 150 is used to adjust the volume. It is determined whether the value has been changed (step 105). If the initialization process has not been performed (immediately after the automatic volume adjustment function is enabled and a negative determination is made in the determination in step 104), or the up / down key 154 provided in the operation unit 150 is pressed. When the volume adjustment value VOL is changed by pressing the button (when an affirmative determination is made in the determination in step 105), the ambient noise measuring unit 133 measures the ambient noise level (step 106) to determine the vehicle interior state. The determination unit 134 calculates and records the vehicle interior state X0 that serves as a reference for determining the vehicle interior state transition Y (step 10).
7). As described above, the vehicle interior state X0 recorded here is obtained by subtracting the ambient noise level BGN from the amplifier gain G (equal to the volume adjustment value VOL at this point).

After the recording of the reference vehicle interior state X0 is completed, or when the volume adjustment value is not changed and a negative determination is made in step 105,
Next, the ambient noise measuring unit 133 measures the ambient noise level (step 108), and the vehicle interior condition determining unit 13
4 calculates and records the vehicle interior state X at that time, which is necessary for determining whether or not to control the volume (step 109).

Next, the vehicle interior state determination unit 134 determines the vehicle interior state transition Y by subtracting the vehicle interior state X at the time recorded in step 109 from the reference vehicle interior state X0 recorded in step 107. Yes (Step 11
0). In addition, the cumulative stimulus amount updating unit 135 performs step 10
The cumulative stimulus amount V is updated by adding the product value of the ambient noise level BGN measured in 8 and the function continuation time T measured using the clock 160 to the cumulative stimulus amount V ′ up to that point. Perform (step 111).

Next, the amplifier gain adjusting section 136 adjusts the amplifier gain G based on the vehicle interior state transition Y, the function continuation time T and the integrated stimulation amount V (step 112).
As described above, (1) when the vehicle interior state transition Y is 0, G × f (T, V) is set as a new amplifier gain G,
(2) When the vehicle interior state transition Y is other than 0, (G +
Let Y) × f (T, V) be a new amplifier gain G. When the amplifier gain G is adjusted and changed, the volume adjustment value VOL is also changed by the same amount. When the adjustment of the amplifier gain G is completed in this way, Step 1
Returning to step 03, the gain of the amplifier 120 is adjusted using the adjusted amplifier gain, and the audio sound is output from the speaker 230.

As described above, the volume correction device 1 of the present embodiment
In 00, the integrated stimulus amount V is calculated in order to determine the degree of fatigue of the auditory system using the ambient noise, and the amplifier gain G is adjusted using the integrated stimulus amount V. Therefore, since the audio sound is listened to for a long time in an environment with a large amount of ambient noise, it becomes possible to set the appropriate amplifier gain G even when the user's auditory fatigue is severe, and suddenly the ambient noise It is possible to reduce the sense of discomfort felt by the auditory sense when the level is lowered.

For example, when correcting the amplifier gain G, if the vehicle interior state transition Y is other than 0, calculating G + Y to obtain a new G corresponds to the conventional sound volume correcting operation. In the present embodiment, the value of G + Y itself is not used, but the function continuation time T is multiplied by the function f depending on the integrated stimulus amount V. Therefore, the amplifier gain correction is performed in consideration of the degree of fatigue of the auditory system. Since the value can be set, even if the level of ambient noise suddenly drops from a state where the auditory system is heavily fatigued by listening to the audio sound for a long time in an environment with high ambient noise, Instead of lowering the amplifier gain G by the amount of change in noise, the amount of lowering the amplifier gain G is set small in consideration of the degree of fatigue of the auditory system. As a result, it is possible to eliminate a sense of incongruity in hearing that the audio sound suddenly feels low due to fatigue of the auditory system.

FIG. 3 shows a volume correction apparatus 100 according to this embodiment.
It is a figure which shows the result of amending an amplifier gain with. In FIG. 3, A indicates an amplifier gain that is actually set by using the volume correction apparatus 100 of the present embodiment, B indicates a gain of an audio audio sound, and C indicates a range where the ambient noise level is high. . When listening to the audio sound for a long time in an environment where the ambient noise level is high, fatigue of the auditory system occurs. Therefore, even when this high ambient noise is eliminated (range D), Considering the degree of fatigue, as shown in FIG. 3, the actual amplifier gain G
Is set to be small so that the audio sound can be heard at a constant auditory level.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, in the embodiment described above,
The case where the function f for correcting the amplifier gain G depends on the function duration T and the integrated stimulus amount V has been described. However, since the fatigue of the auditory system changes depending on the frequency of the audio sound, the frequency of the audio sound is measured, Function duration time T
In addition to the cumulative stimulus amount V, a function f depending on frequency may be used.

In the above-described embodiment, the audio sound is considered as the correction target sound, but the present invention is also applied to the case of correcting the level of the sound of the other kind than the guide voice output from the navigation device or the like. can do.

[0033]

As described above, according to the present invention, the degree of auditory fatigue is determined based on the ambient noise and the volume of the voice is changed. It becomes possible to set the appropriate volume even when the auditory system is heavily fatigued by listening to the sound, and to reduce the discomfort felt by the hearing when the ambient noise level suddenly decreases. You can

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a volume correction device according to an embodiment.

FIG. 2 is a flowchart showing an operation procedure of a volume adjusting operation by the volume correcting device.

FIG. 3 is a diagram showing a result of correcting an amplifier gain by the volume correction device of the present embodiment.

FIG. 4 is a diagram showing an outline of a conventional volume correction device that does not consider fatigue of the auditory system.

FIG. 5 is a diagram showing an outline of a conventional volume correction device that does not consider fatigue of the auditory system.

[Explanation of symbols]

100 Volume correction device 110 changeover switch 120 amp 130 control unit 131 Source Selector 132 Volume setting section 133 ambient noise measurement section 134 Vehicle interior condition determination unit 135 Cumulative stimulation amount update section 136 Amplifier gain adjustment section 140 microphone 150 control panel 160 clock

Claims (4)

[Claims] 1. A sound collecting unit installed at a predetermined position in an acoustic space, a fatigue judging unit judging an auditory fatigue level based on ambient noise collected by the sound collecting unit, and the fatigue judging unit. A sound volume correction device, comprising: a sound volume adjustment device that changes the sound volume of the sound to be corrected based on the degree of fatigue determined by the device. 2. The sound volume correction device according to claim 1, wherein the fatigue determination means determines the fatigue level based on a cumulative value of the level of the ambient noise and the elapsed time. 3. The sound volume adjusting means according to claim 1, further comprising a state determining means for determining a state in the acoustic space based on a difference between an actual sound output level and a level of the ambient noise. A volume correction device, wherein the volume is varied based on the degree of fatigue and the state determination result by the state determining means. 4. The volume correction device according to claim 1, wherein the correction target sound is an audio sound output from an audio device mounted on a vehicle.