JP2002369281A - Sound quality volume control device - Google Patents

Abstract

(57) [Problem] To provide a sound quality volume control device that can be heard naturally in terms of audibility even when the levels of a sound source signal and a noise signal change respectively. SOLUTION: A sound source signal level updating means 113 determines an update amount after comparing the sound source signal level calculated by the sound source signal analyzing means 108 with the previous sound source signal level in the band, and updates the updated sound source signal level. The update processing output value is output to the compensation amount calculation means 109. The noise level updating unit 112 determines an update amount after comparing the noise signal level calculated by the noise signal analyzing unit 107 with the previous noise signal level update processing output value in the band, and updates the updated noise signal level. Compensation amount calculating means 10 for processing output value
9 is output. The compensation amount calculation means 109 calculates a compensation amount at regular time intervals using the output value of the sound source signal level update process and the output value of the noise signal level update process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls the frequency characteristic and volume of a sound source signal which is loudspeaked according to a noise signal when there is unnecessary noise in a sound field such as a vehicle interior, a listening room, and a public space. The present invention relates to a sound quality volume control device.

[0002]

2. Description of the Related Art Conventionally, as this kind of sound quality volume control device, there is one described in, for example, JP-A-6-334457. FIG. 10 shows a configuration example of a conventional sound quality volume control device for performing sound reproduction while compensating for masking due to noise.

[0003] In FIG. 10, a sound quality volume control device is C
D (Compact Disc) player, cassette tape, source signal input terminal 701 to which a sound source signal such as radio or announcement is input, noise signal input terminal 706 to which noise collected by a microphone or the like is input, frequency band of the sound source signal Sound source signal analysis means 708 for calculating each level,
Noise signal analysis unit 707, compensation amount calculation unit 709, adjustment amount update unit 710, adjustment amount setting unit 711, frequency characteristic adjustment unit 702 such as an equalizer, and volume of volume and the like for calculating the level of each frequency band of the noise signal An adjusting unit 703, an amplifier 704, and a speaker 705 are provided.

In this sound quality volume control device, a sound source signal such as an announcement or music output from a sound source such as a CD is input to a source signal input terminal 701, and the gain of a plurality of frequency bands is changed by a frequency characteristic adjusting means 702. By doing so, the frequency characteristics are adjusted, and the volume
3, the volume is adjusted, amplified by the amplifier 704, and output by the speaker 705.

[0005] The signal from the source signal input terminal 701 is input to a sound source signal analyzing means 708, and the signal level of the sound source is changed at a predetermined time interval for each of a plurality of predetermined frequency bands. Analyzed
This is one input of the compensation amount calculation means 709.

[0006] In the space where the speaker 705 is installed, a noise signal having a high correlation with ambient noise at or near a listening place where the sound output from the speaker 705 is received is collected by a microphone or the like, and a noise signal input terminal 706 is provided. , And the noise signal level is analyzed at predetermined time intervals by the noise signal analysis means 707 for each of a plurality of preset frequency bands, and the result is input to the other input of the compensation amount calculation means 709.

The compensation amount calculating means 709 calculates the compensation amount at regular time intervals from the masking amount of the sound source signal by the noise signal, the energy ratio between the noise signal and the sound source signal, and the like.

The sound source signal analyzing means 708 and the noise signal analyzing means 707 analyze the data at fixed time intervals, and the compensation amount calculated by the compensation amount calculating means 709 fluctuates with time. If the adjustment amounts of the unit 702 and the volume adjustment unit 703 are used, the hearing becomes unnatural before and after the update of the adjustment amount.

If the time interval for calculating the amount of compensation is long, the adjustment of the sound quality and the volume will be delayed. Conversely, if the time interval is shortened, the adjusted sound source will be perceived as fluctuating.
Therefore, the operation time interval of the compensation amount calculating unit 709 is set to be longer from several tens of milliseconds to several seconds, and the adjustment amount updating unit 710
, The integration of the output signal of the compensation amount calculating means 709,
By using an average or an LPF (Low Pass Filter), the adjustment of the frequency characteristic adjusting unit 702 and the volume adjusting unit 703 is smoothly updated.

The adjustment amount setting means 711 calculates the filter coefficients and refers to a table to set the adjustment amounts of the frequency characteristic adjusting means 702 and the volume adjusting means 703. The frequency characteristic adjusting means 702 and the volume adjusting means 703 control the sound source signal. Control sound quality and volume.

As described above, by changing the frequency characteristics and the sound volume of the sound source signal according to the characteristics of the detected sound source signal and the characteristics of the ambient noise, even if the ambient noise exists, the characteristics of the ambient noise change. Can be reproduced so as to be heard at the same loudness as when there is no ambient noise.

[0012]

However, in such a conventional sound quality volume control apparatus, when the level of the sound source signal changes gradually, the sound is naturally heard from the auditory sense, but the levels of the sound source signal and the noise signal change respectively. In this case, if the time constant for updating the adjustment amount is increased so as not to follow the minute fluctuation of the noise signal, for example, the tracking of the compensation of the audio signal in syllable units may not be performed in time. Had.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and provides a sound quality volume control device that can be heard naturally in terms of audibility even when the levels of a sound source signal and a noise signal change respectively. It is.

[0014]

The sound quality and volume control device of the present invention detects the level of a sound source signal at a constant cycle, compares the level of the detected sound source signal with the level output at the previous cycle, and makes a comparison. Sound source signal level updating means for determining the level of the sound source signal to be output based on the result of the detection, detecting the level of the noise signal at a constant cycle, and comparing the level of the detected noise signal with the level output in the previous cycle. A noise level updating unit that determines the level of the noise signal to be output based on the comparison result; a sound source signal level output by the sound source signal level updating unit; and a noise signal level output by the noise level updating unit. A compensation amount calculating means for calculating a compensation amount for adjusting the sound source signal based on the compensation amount. With this configuration, the level of the sound source signal is output based on the comparison result of the detected sound source signal level and the level output in the previous cycle, and the result of the comparison between the detected noise signal level and the level output in the previous cycle is output. The level of the noise signal is output based on this, and the sound source signal is adjusted based on these.

Here, it is preferable to provide an adjustment amount updating means for updating the adjustment amount in a stepwise manner so that the sound quality does not deteriorate at the change point of the adjustment amount of the sound source signal based on the compensation amount.

With this configuration, the adjustment amount is updated stepwise at the change point of the adjustment amount of the sound source signal.

Further, the sound source signal level updating means may be arranged such that the difference between the level of the detected sound source signal and the level output in the previous cycle is smaller than a predetermined upper limit value of the level and smaller than a predetermined lower limit value of the level. If it is larger, the level output in the previous cycle is output.If the difference between the level of the detected sound source signal and the level output in the previous cycle is equal to or greater than the level upper limit, the level of the detected sound source signal is output. If the difference between the level of the detected sound source signal and the level output in the previous cycle is equal to or less than the level lower limit value, the level output in the previous cycle is output, and the detected sound source is output continuously for a preset number of times. When the difference between the signal level and the level output in the previous cycle is equal to or less than the level lower limit value, a preset level decrease value is subtracted from the level output in the previous cycle. It is preferable to output the level.

According to this configuration, the level is not updated with a minute change in the sound source signal level, the level is updated with a short time interval when the sound source signal level increases, and with a long time interval when the sound source signal level decreases. The level will be updated.

The sound source signal level updating means may set the level of the detected sound source signal in advance when the difference between the detected sound source signal level and the level output in the previous cycle is equal to or higher than the level upper limit value. A level obtained by adding the level increase value may be output.

With this configuration, if the difference between the level of the detected sound source signal and the level output in the previous cycle is equal to or greater than the level upper limit value, the level is updated with the level increase value.

It is preferable that the level decrease value is smaller than the level increase value. With this configuration, when the level of the audio signal rises, the level can be largely changed with a smaller number of updates than when the level falls.

The noise level updating means may be arranged so that the difference between the level of the detected noise signal and the level output in the previous cycle is smaller than a predetermined noise level upper limit value and a predetermined noise level lower limit value. If it is greater than, the level output in the previous cycle is output, and if the difference between the level of the detected noise signal and the level output in the previous cycle is equal to or less than the noise level lower limit, the level of the detected noise signal is A level obtained by subtracting a predetermined noise level drop value is output, and if the difference between the level of the detected noise signal and the level output in the previous cycle is equal to or higher than the noise level upper limit value, the level output in the previous cycle. And when the difference between the level of the detected noise signal and the level output in the previous cycle is equal to or greater than the noise level upper limit value for a preset number of times. It is preferred that outputs a level obtained by adding a preset noise level rise value to a level that is output in the previous cycle.

According to this configuration, the level is not updated when the noise signal level is minutely changed, the level is updated at a short time interval when the noise signal level decreases, and at a long time interval when the noise signal level increases. The level will be updated.

Further, the noise level updating means, if the difference between the level of the detected noise signal and the level output in the previous cycle is equal to or greater than the noise level upper limit value for a preset number of times, The level output in a cycle may be output.

With this configuration, if the difference between the level of the detected noise signal and the level output in the previous cycle is equal to or greater than the noise level upper limit value for a predetermined number of times, the level output in the previous cycle is output. Will be done.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 are diagrams showing a sound quality volume control device according to a first embodiment of the present invention.

As shown in FIG. 1, a sound quality volume control device according to the present embodiment includes a source signal input terminal 101 to which a sound source signal such as a CD (Compact Disc) player, a cassette tape, a radio or an announcement is input, an equalizer, and the like. A frequency signal adjusting means 102, a volume adjusting means 103 such as a volume, an amplifier 104, a speaker 105, a noise signal input terminal 106 to which noise collected by a microphone or the like is inputted.
Noise signal analyzing means 107 for calculating the level of each frequency band of the noise signal, sound source signal analyzing means 108 for calculating the level of each frequency band of the sound source signal, compensation amount calculating means 109, adjustment amount updating means 110, Adjustment amount setting means 1
11, a noise level updating unit 112 and a sound source signal level updating unit 113.

In this sound quality volume control device, a sound source signal such as an announcement or music output from a sound source such as a CD is input to a source signal input terminal 101, and the gain of a plurality of frequency bands is changed by a frequency characteristic adjusting means 102. By doing so, the frequency characteristic is adjusted, and
3, the volume is adjusted, amplified by the amplifier 104, and output by the speaker 105.

The sound source signal input to the source signal input terminal 101 is also input to the sound source signal analyzing means 108, where the signal level of the sound source is changed for each of a plurality of preset frequency bands. It is analyzed at regular time intervals and output to the sound source signal level updating means 113.

Upon receiving the sound source signal level calculated by the sound source signal analyzing means 108, the sound source signal level updating means 113 compares the stored sound source signal level with the previous output value of the sound source signal level updating process in that band and updates the amount. Is determined, and the output value of the sound source signal level update processing is updated and stored. Then, the updated sound source signal level update processing output value is output to the compensation amount calculation means 109.

Next, in a space where the speaker is installed, a noise signal having a high correlation with ambient noise at a listening place where the sound output from the speaker is listened or in the vicinity thereof is collected by a microphone or the like, and a noise signal input terminal is provided. 10
6 is analyzed by the noise signal analyzing means 107 at predetermined time intervals for each of a plurality of predetermined frequency bands, and is output to the noise level updating means 112.

When the noise level updating means 112 receives the noise signal level calculated by the noise signal analyzing means 107, the noise level updating means 112 compares the stored noise signal level with the previous output value of the noise signal level update processing in the band, and then updates the update amount. It is determined, and the noise signal level processing output value is updated and stored. Then, the updated noise signal level update processing output value is output to the compensation amount calculation means 109.

The compensation amount calculation means 109 uses the sound source signal level update processing output value and the noise signal level update processing output value to calculate, for example, the masking amount of the sound source signal by the noise signal, the energy ratio of the noise signal to the sound source signal, and the like. , The compensation amount is calculated at regular time intervals.

Since the compensation amount calculated by the compensation amount calculating means 109 fluctuates with time, if the compensation amount is used as the adjustment amount of the frequency characteristic adjusting means 102 and the volume adjusting means 103 as it is, before and after updating the adjustment amount. It becomes unnatural in hearing.

Further, if the time interval of the compensation amount calculation is long, the adjustment of the sound quality and the volume will be delayed. Conversely, if the time interval is shortened, the adjusted sound source will be perceived as fluctuating.
For this reason, the operation time interval of the compensation amount calculating means 109 is set to be as long as several tens of milliseconds to several seconds, and the adjustment amount updating means 110
, The integration of the output signal of the compensation amount calculating means 109,
The average and the adjustment of the frequency characteristic adjusting unit 102 and the volume adjusting unit 103 are smoothly updated by using an LPF (Low Pass Filter).

The adjustment amount setting means 111 calculates the filter coefficients and refers to a table to set the adjustment amounts of the frequency characteristic adjusting means 102 and the volume adjusting means 103. Control sound quality and volume.

Next, the updating of the sound source signal level by the sound source signal level updating means 113 will be described.

First, the analysis time interval to be considered will be described. First, since the sound source signal fluctuates every moment, if the analysis time interval of the sound source signal level is set to be less than one hundred and several tens of milliseconds, the sound source signal level calculated for each time interval slightly fluctuates, and this fluctuates. When the compensation amount is calculated using the sound source signal level, the calculated compensation amount also slightly fluctuates, and the source signal fluctuates and is reproduced. Further, when the sound source signal is a voice, a large level fluctuation occurs in the sound part and the silent part, and if the compensation amount is calculated using the sound source signal that fluctuates greatly, the calculated compensation amount also largely fluctuates. Will be.

Second, if the analysis time interval is increased to several seconds, the voice level remains constant during the analysis time interval and there is no minute fluctuation, but attention is focused on consonants and syllables that improve the clarity of voice. The fine tracking ability is reduced.

For the above reasons, in the present embodiment, the analysis time interval is set short in order to ensure follow-up performance, and the unnaturalness of compensation caused by minute or large fluctuations of the sound source signal caused by setting the analysis time interval short. To eliminate the noise, the currently calculated sound source signal level is compared with the previously output sound source signal level update processing output value, and the current sound source signal level is compared with the previously calculated sound source signal level update processing output value. In some cases, the sound source signal level update processing output value is output without being updated.

When the input sound source signal level is larger than the previously calculated output value of the sound source signal level update processing, the input sound source signal level is output as it is. When the calculated sound source signal level update processing output value is smaller than the output value, the sound source signal level is updated so as to be gradually closer to the input sound source signal level, so that it does not follow minute fluctuations and level fluctuations in silent sections. To update the sound source signal level.

Next, the updating of the noise level by the noise level updating means 112 will be described.

First, the analysis time interval to be considered will be described. First, since the noise signal level fluctuates every moment, if the analysis time interval of the noise signal level is set to be less than one hundred and several tens of milliseconds, the noise signal level calculated at each time interval slightly fluctuates. When the compensation amount is calculated using the noise signal level which fluctuates minutely, the calculated compensation amount also fluctuates minutely, and the source signal fluctuates and is reproduced. Second, if you increase the analysis time interval to a few seconds,
During the analysis time interval, the noise signal level is constant and there is no small fluctuation, but the follow-up to the change in the noise characteristic is reduced.

For the above reasons, in the present embodiment, the analysis time interval is set short in order to ensure the follow-up performance, and the unnaturalness of compensation due to the minute fluctuation of the noise signal level caused by the short setting is eliminated. Therefore, the currently calculated noise signal level is compared with the previously calculated noise signal level update processing output value, and if the current noise level is merely a small fluctuation compared to the previously calculated noise signal level update processing output value, If the noise signal level is not updated, and if it is not a minute fluctuation, the noise signal level is updated so as to gradually approach the input noise signal level, and does not follow the minute fluctuation of the noise signal level. If the level changes, follow it quickly.

As described above, the compensation amount calculating means 109 uses the smoothly updated sound source signal level and noise signal level.
By calculating the compensation amount in the above, the compensation amount for the sound source signal can be changed without a sense of incongruity, and the sound source signal can be reproduced naturally in terms of audibility.

FIG. 2 is a flowchart showing a processing flow of the sound source signal level updating means 113. The operation procedure of the sound source signal level updating means 113 will be described with reference to FIG.

The sound source signal level updating means 113 first
When the current sound source signal level S calculated by the sound source signal analyzing means 108 is input (S11), the difference between the input S and the previous sound source signal level update processing output value Sout is determined by a predetermined update condition. Whether it is larger than the lower limit value ThreLow (level lower limit value) and smaller than the upper limit value ThreUp (level upper limit value) of the preset update condition (ThreLow <S-Sout <ThreU)
p) is determined (S12), and S-Sout is greater than ThreLow,
If it is smaller than ThreeUp, it is determined that the sound source signal level is slightly fluctuating, and the counter C is cleared to 0 (S2).
0) Sout is output without updating the previous sound source signal level update processing output value Sout (S21), and waits for the next input.

When S-Sout is equal to or less than ThreLow or equal to or more than ThreUp, it is determined that the sound source signal level is largely changed, and it is determined whether the sound source signal level is decreasing or increasing. Is greater than or equal to ThreUp (S1
3). If S-Sout is equal to or greater than ThreeUp, it is recognized that the sound source signal level is rising, so the counter C is cleared to 0 (S14), and the current sound source signal level S is set to a new output value Snew (S15). ) And set Snew to Sout (S1
9) Output Sout (S21).

If S-Sout is not equal to or greater than ThreeUp, the sound source signal level is recognized to be falling. Therefore, it is determined whether or not the sound source signal level drops after a certain period of time longer than the time when the sound source signal level is determined to fall. C for determining
Is incremented by 1 (S16), and it is determined whether the counter C is equal to or larger than a preset value n (S17).

If the counter C is smaller than n, Sout is output without updating the previous sound source signal level update processing output value Sout (S21), and the next input is waited.

If the counter C is equal to or more than n, it is determined that the sound source signal level is continuously dropping, and a preset value Ldown is obtained from the previous sound source signal level update processing output value Sout.
The difference obtained by subtracting the (level lowering value) is set to a new output value Snew (S18), Snew is set to Sout (S19), and Sout is output (S21).

When it is determined in S15 that the sound source signal level has risen, the current sound source signal level S is set as a new output value Snew. The update process may be performed so that the output value is increased by the set value Lup (level increase value). In this case, Ldown <Lup may be set in order to improve the follow-up performance when the sound source signal level rises more than when it falls.

FIG. 3 is a flowchart showing the processing flow of the noise level updating means 112. The operation procedure of the noise level updating means 112 will be described with reference to FIG.

First, when the current noise level N calculated by the noise signal analyzing means 107 is input (S 31), the noise level updating means 112 calculates the input N and the previous noise signal level update processing output value Nout. Is larger than the lower limit NthreLow (sound level lower limit) of the preset update condition and smaller than the upper limit NthreUp (sound level upper limit) of the preset update condition (NThreLow <N-Nout < NT
hreUp) is determined (S32), and if N-Nout is greater than NThreLow and smaller than NThreUp, it is determined that the noise signal level is slightly fluctuating, and the counter C is cleared to 0 (S40). Nout is output without updating the level update processing output value Nout (S41), and the next input is waited for.

When S-Sout is equal to or less than ThreLow or equal to or greater than ThreUp, it is determined that the noise signal level is largely changed, and it is determined whether the noise signal level is decreasing or increasing. Is lower than NthreLow (S
33). If N-Nout is equal to or less than ThreLow, it is recognized that the noise signal level is decreasing. Therefore, the counter C is cleared to 0 (S34), and a preset value Nldown (noise level) is obtained from the current noise signal level N. The difference obtained by subtracting the falling value is set to a new output value Nnew (S35), Nnew is set to Nout (S39), and Nout is output (S41).

If N-Nout is not less than NthreLow, it is recognized that the noise signal level has increased. Therefore, it is determined whether the noise signal level has increased after a lapse of a certain period of time longer than the time when the increase in the noise signal level is determined. Is incremented by one (S36), and it is determined whether the counter C is equal to or greater than a preset value n (S37).

If the counter C is smaller than n, Nout is output without updating the previous noise signal level update processing output value Nout (S41), and the next input is waited.

If the counter C is equal to or more than n, it is determined that the noise signal level is continuously increasing, and a preset value Nlup is calculated from the previous noise signal level update processing output value Nout.
The sum of (noise level rise value) is set to a new output value Nnew (S38), Nnew is set to Nout (S39), and No
ut is output (S41).

As described above, by making the determination time when the noise signal level rises longer, that is, by making the time constant for updating the noise signal level larger than that when the noise signal level falls, sudden noise level fluctuations can be prevented. Will not follow. On the other hand, when the noise signal level decreases, the noise signal level can be quickly updated and the compensation amount can be changed without a sense of incongruity.

When it is determined in S35 that the sound source signal level is falling, the output value is reduced by a preset value NLdown from the previous noise signal level update processing output value Nout as a new output value Nnew. However, an update process may be performed to set the current noise signal level N.

Further, as another configuration example of the sound source signal level updating means 113, the inputted sound source signal level is held over several past times, and the maximum value is used as the output value of the sound source signal level updating process. It is possible not to follow a minute change of the sound source and a silent section.

As described above, according to the present embodiment, the sound source signal level updating means 113 for smoothly updating the level change of the sound source signal, and the noise level updating means 112 for smoothly updating the level change of the ambient noise. And a compensation amount calculating means 109 for calculating a compensation amount for compensating a frequency characteristic and a sound volume of the sound source signal according to the ambient noise, and a time constant and update corresponding to the time change characteristics of the sound source signal and the noise signal. Since the sound source signal level and the noise signal level are updated by separately setting the amounts and the compensation amount is calculated, even if there is ambient noise or the characteristics of the ambient noise change,
The sound source can be reproduced so as to be heard at the same loudness as when there is no ambient noise, and even when the sound source signal level and the noise signal level change, the sound source signal can be reproduced naturally in terms of audibility.

As another aspect of the present embodiment, as shown in FIG. 4, the adjustment amount updating means 110 is deleted. When a BGM with a small level fluctuation or a guidance voice of an in-vehicle navigation system is used as the sound source signal, the sound source signal level updating unit 113 updates the sound source signal level by using
Even if the above-mentioned update amounts Lup and Ldown are made small, it is possible to sufficiently follow up, so that the output of the sound source signal level update process changes sufficiently smoothly. Therefore, the compensation amount calculated from such updated sound source signal level and noise signal level also changes smoothly, and even if the adjustment amount updating unit 110 is removed, the sound quality deterioration at the change point of the adjustment amount is not a problem of hearing. No.

That is, by calculating the amount of compensation using the smoothly updated sound source signal level and noise signal level, the amount of compensation for the sound source signal can be changed without a sense of incongruity, and the sound source signal can be reproduced naturally in terms of audibility. can do.

Next, FIG. 5 is a diagram showing a sound quality volume control device according to a second embodiment of the present invention. In the present embodiment, the frequency characteristic adjusting unit 102, the volume adjusting unit 103, and the noise signal analyzing unit 1 in the first embodiment described above.
07, sound source signal analysis means 108, compensation amount calculation means 10
9. A program that operates as the adjustment amount updating unit 110 and the adjustment amount setting unit 111 is created.

In FIG. 5, a CPU (Central Process
ng Unit) 207, a bus 212 is derived,
ROM in which boot program and the like are stored in bus 212
(Read-Only Memory) 211 and RA for main memory
An M (Random Access Memory) 210 is connected.

The bus 212 has an interface 2
A / D converters 203 and 204 for converting analog signals to digital signals and a D / A converter 209 for converting digital signals to analog signals are connected via 08.

The A / D converter 203 has a sound source 20 such as a CD player, a cassette tape, a radio or an announcement.
1 is connected, and the microphone 2 is connected to the A / D converter 204.
02 is connected to the D / A converter 209.
5. The speaker 206 is connected.

In such a sound quality and volume control device, the signal from the sound source 201 is converted into a digital signal by the A / D converter 203, and the ambient noise signal from the microphone 202 is converted into a digital signal by the A / D converter 204. I do.

The digital signals converted by the A / D converters 203 and 204 are sent to the CP via the interface 208.
The signal processing of the operation described in the first embodiment is performed by U207, and the frequency characteristic and the volume of the sound source signal are adjusted.
The converter 209 converts the digital signal into an analog signal.

The sound source signal output from D / A converter 209 is amplified by amplifier 205 and output to speaker 206.

As described above, according to the present embodiment, the amount of compensation is calculated using the sound source signal level and the noise signal level that have been smoothly updated by software, so that the amount of compensation for the sound source signal can be changed without a sense of incongruity. Thus, the sound source signal can be reproduced naturally in terms of audibility.

Next, FIG. 6 is a diagram showing a communication device according to a third embodiment of the present invention. In this embodiment, since the configuration is substantially the same as that of the above-described first embodiment, the same components are denoted by the same reference numerals and only the characteristic portions will be described.

As shown in FIG. 6, the communication apparatus according to the present embodiment is connected to antenna 303 and receives a transmission / reception section 301 for performing wireless communication via antenna 303 and an audio signal to be transmitted to transmission / reception section 301. And a microphone 302.

In this communication apparatus, the source signal input terminal 101 of FIG. 1 is connected to a terminal from which the transmitting / receiving section 301 outputs the audio signal received from the antenna 303, and the noise signal input terminal 106 is connected to the output terminal of the microphone 302. ing.

As described above, according to the present embodiment, the compensation amount is calculated for the received sound of the communication device and the noise included in the microphone signal using the smoothly updated received signal level and noise signal level. As a result, the amount of compensation for the received signal can be changed without discomfort, and the received sound can be reproduced naturally in terms of hearing.

Next, FIG. 7 is a diagram showing an acoustic device according to a fourth embodiment of the present invention. In this embodiment, since the configuration is substantially the same as that of the above-described first embodiment, the same components are denoted by the same reference numerals and only the characteristic portions will be described.

As shown in FIG. 7, the audio device of this embodiment has a user interface 401, a CD 402,
An FM tuner 403, a sound source selector 404, and a microphone 405 are provided, and the source signal input terminal 10 shown in FIG.
1 is connected to the output terminal of the sound source selector 404, and the noise signal input terminal 106 is connected to the output terminal of the microphone 405.

In this acoustic device, the user operates the user interface 401 to determine the type and volume of the sound source. The type of the sound source is notified to the sound source selector 404, and the output of the CD 402, the FM tuner 403, or the like is selected. Further, the frequency characteristic and the sound volume of the sound source characteristics are adjusted by the frequency characteristic adjusting unit 102 and the volume adjusting unit 103 according to the user's preference.

As described above, according to the present embodiment, the compensation amount is calculated using the sound source signal level and the noise signal level that have been smoothly updated, so that the compensation amount for the sound source signal can be changed without discomfort. Therefore, the sound source signal can be reproduced naturally in terms of audibility.

Next, FIG. 8 is a diagram showing an information terminal device according to a fifth embodiment of the present invention. In this embodiment,
Since the configuration is substantially the same as that of the above-described first embodiment, the same components are denoted by the same reference numerals, and only the features will be described.

As shown in FIG. 8, the information terminal device of the present embodiment includes a bus 512
A ROM 502 in which a boot program and the like are stored and a RAM 503 for a main memory are connected.

The bus 512 has a storage device 504 such as a memory card or a hard disk drive.
Is connected, and a communication device 506 such as a terminal adapter or a modem or a network interface card is connected via the interface 505.
A display 508 is connected via a driver 507, and an input device 510 such as a keyboard, a touch panel, and a mouse is connected via a driver 509.

The bus 512 is connected to the source signal input terminal 101 of FIG. 1 via the interface 511, and the noise signal input terminal 106 is connected to the microphone 513.
Connected to the output terminal. The D / A converter 514 is connected between the volume control unit 103 and the amplifier 104.

This information terminal device can be used as a sound source signal for a storage device 5 such as a memory card or a hard disk.
The sound source data stored in the interface 04
You are typing through.

As described above, according to the present embodiment, the sound source signal level and the noise signal level that are smoothly updated are changed with respect to the respective changes in the level of the sound source signal and the ambient noise signal level reproduced by the information terminal device. By calculating the compensation amount by using this, the compensation amount for the sound source signal can be changed without a sense of incongruity, and the sound source signal can be reproduced naturally in terms of audibility.

Next, FIG. 9 is a diagram showing a vehicle-mounted navigation device according to a sixth embodiment of the present invention. In this embodiment, since the configuration is substantially the same as that of the above-described first embodiment, the same components are denoted by the same reference numerals and only the characteristic portions will be described.

As shown in FIG. 9, the on-vehicle navigation device according to the present embodiment includes a bus 615 derived from a CPU 601 and a ROM 602 in which a boot program and operation programs of the device are stored. A main memory RAM 603 for temporarily storing data is connected.

The bus 615 has a current position detecting means 604 for detecting information on the current position of the vehicle, and a route searching means for searching for a route from the current position using the facility name selected by voice recognition as the destination of the vehicle. 605, a map storage unit 606 for storing map data, a voice recognition unit 607 for performing voice recognition using a microphone input signal, a voice synthesis unit 608 for generating route guidance and guidance voice used in a user interface, and a display via a driver 609. 61
0, an input device 612 such as a microphone, a keyboard, a touch panel, and a mouse used for voice recognition is connected via a driver 611.

Further, the source signal input terminal 101 of FIG. 1 is connected to the bus 615 via the interface 614, and the noise signal input terminal 106 is connected to the interface 61.
3 and a D / A converter 616 is connected between the volume control means 103 and the amplifier 104.

[0091] This car navigation system uses a guidance voice as a sound source signal and a signal input from a voice recognition microphone as a noise signal.

As described above, according to the present embodiment, the level of the sound source signal such as the guidance sound reproduced by the on-vehicle navigation device and the level of the ambient noise signal detected by the voice recognition microphone are respectively changed. By calculating the compensation amount using the sound source signal level and the noise signal level that have been smoothly updated, the compensation amount for the sound source signal can be changed without discomfort, and the sound source signal can be reproduced naturally in terms of audibility.

[0093]

As described above, the present invention updates the sound source signal level and the noise level by separately setting the time constant and the update amount according to the time change characteristics of the sound source signal and the noise signal. By calculating the compensation amount, even if there is ambient noise, and even if the characteristics of the ambient noise change, the sound is reproduced so as to be heard at the same loudness as when there is no ambient noise, and the sound source signal level and It is possible to provide a sound quality volume control device capable of reproducing a sound source signal naturally in terms of audibility even when the noise level changes.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a sound quality volume control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a sound source signal level updating process of the sound quality volume control device according to the first embodiment of the present invention;

FIG. 3 is a flowchart showing a noise signal level updating process of the sound quality volume control device according to the first embodiment of the present invention;

FIG. 4 is a schematic block diagram showing a sound quality volume control device according to another aspect of the first embodiment of the present invention;

FIG. 5 is a schematic block diagram showing a sound quality volume control device according to a second embodiment of the present invention;

FIG. 6 is a schematic block diagram showing a communication device according to a third embodiment of the present invention.

FIG. 7 is a schematic block diagram showing an acoustic device according to a fourth embodiment of the present invention.

FIG. 8 is a schematic block diagram showing an information terminal device according to a fifth embodiment of the present invention.

FIG. 9 is a schematic block diagram showing a vehicle-mounted navigation device according to a sixth embodiment of the present invention.

FIG. 10 is a schematic block diagram showing a conventional sound quality volume control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Source signal input terminal 102 Frequency characteristic adjusting means 103 Volume adjusting means 104 Amplifier 105 Speaker 106 Noise signal input terminal 107 Noise signal analyzing means 108 Sound source signal analyzing means 109 Compensation amount calculating means 110 Adjustment amount updating means 111 Adjusting amount setting means 112 Noise Level updating means 113 Sound source signal level updating means 201 Sound source 202 Microphone 203, 204 A / D converter 205 Amplifier 206 Speaker 207 CPU (Central Processing Unit) 208 Interface 209 D / A converter 210 RAM (Random Access Memory) 211 ROM ( Read-Only Memory) 212 Bus 301 Transceiver 302 Microphone 303 Antenna 401 User Interface 402 CD 403 FM Tuner 404 Sound Source Selector 405 Micro 501 CPU 502 ROM 503 RAM 504 Storage device 505 Interface 506 Communication device 507 Driver 508 Display 509 Driver 510 Input device 511 Interface 512 Bus 513 Microphone 514 D / A converter 601 CPU 602 ROM 603 RAM 604 Current position detection means 605 Route search Means 606 Map storage means 607 Voice recognition means 608 Voice synthesis means 609 Driver 610 Display 611 Driver 612 Input device 613 Interface 614 Interface 615 Bus 616 D / A converter 701 Source signal input terminal 702 Frequency characteristic adjustment means 703 Volume adjustment means 704 Amplifier 705 Speaker 706 Noise signal input terminal 7 7 noise signal analyzing means 708 source signal analyzing means 709 compensation amount calculating means 710 adjustment amount updating means 711 adjustment amount setting means

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 5D020 AC05 5J030 AA01 AA10 AB01 AC09 AC10 AC16 AC17 AC20 AC21 AC23 AC25 5J100 JA06 KA05 LA04 LA09 LA11 LA12 QA02 SA06

Claims (7)

[Claims] 1. A level of a sound source signal is detected at a constant cycle, a level of the detected sound source signal is compared with a level output at a previous cycle, and a level of the sound source signal to be output is determined based on a result of the comparison. Sound source signal level updating means for detecting the level of the noise signal at a constant cycle, comparing the level of the detected noise signal with the level output in the previous cycle, and determining the level of the noise signal to be output based on the comparison result. Noise level updating means for determining a level; compensation for calculating a compensation amount for adjusting a sound source signal based on a sound source signal level output by the sound source signal level updating means and a noise signal level output by the noise level updating means. A sound quality volume control device comprising: a volume calculation unit. 2. The apparatus according to claim 1, further comprising an adjustment amount updating unit that updates the adjustment amount in a stepwise manner so that sound quality does not deteriorate at a change point of the adjustment amount of the sound source signal based on the compensation amount. Sound quality volume control device. 3. The sound source signal level updating means according to claim 1, wherein the difference between the detected sound source signal level and the level output in the previous cycle is smaller than a preset level upper limit value and is smaller than a preset level lower limit value. If it is larger, the level output in the previous cycle is output.If the difference between the level of the detected sound source signal and the level output in the previous cycle is equal to or greater than the upper limit level, the level of the detected sound source signal is output. If the difference between the level of the detected sound source signal and the level output in the previous cycle is equal to or less than the level lower limit value, the level output in the previous cycle is output, and the detected sound source is continued for a preset number of times. When the difference between the signal level and the level output in the previous cycle is equal to or less than the level lower limit value,
3. The sound quality volume control device according to claim 1, wherein a level obtained by subtracting a preset level decrease value from a level output in a previous cycle is output. 4. The sound source signal level updating means, wherein when the difference between the detected sound source signal level and the level output in the previous cycle is equal to or greater than the level upper limit value, the detected sound source signal level is set in advance. The sound quality volume control device according to claim 3, wherein a level obtained by adding the level rise value is output. 5. The sound quality volume control device according to claim 4, wherein the level decrease value is smaller than the level increase value. 6. The noise level updating means, wherein the difference between the level of the detected noise signal and the level output in the previous cycle is smaller than a preset noise level upper limit value and a preset noise level lower limit value. If it is larger, the level output in the previous cycle is output, and if the difference between the level of the detected noise signal and the level output in the previous cycle is equal to or less than the noise level lower limit, the level of the detected noise signal is A level obtained by subtracting a preset noise level drop value is output, and if the difference between the level of the detected noise signal and the level output in the previous cycle is equal to or greater than the noise level upper limit value, the level output in the previous cycle. And, when the difference between the level of the detected noise signal and the level output in the previous cycle is equal to or greater than the noise level upper limit value for a preset number of times, The sound quality volume control device according to any one of claims 1 to 5, which outputs a level obtained by adding a preset noise level increase value to the level output in the cycle of (1). 7. The noise level updating means, if the difference between the level of the detected noise signal and the level output in the previous cycle is equal to or greater than the noise level upper limit value for a preset number of times, 7. The sound quality volume control device according to claim 6, wherein a level output in a cycle is output.