JP3411648B2 - Automotive audio equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted audio device, and more particularly to a vehicle-mounted audio device that enables smooth conversation while listening to audio. 2. Description of the Related Art In recent years, on-board audio devices include CDs,
Digital audio sources such as DAT, MD, DCC and the like have been used to enhance the sound quality, and high power amplifiers have been used to increase the sound volume, making the system comparable to home audio. Also, it is customary that one set of left and right speakers is installed on the front side and one set of left and right speakers is installed on the rear side. [0003] However, with the enhancement of such in-vehicle audio devices, even if the volume is increased, sound can be reproduced without distortion, so that there is a tendency to listen to music with the volume increased. Yes, if some people are playing music while riding, the speaker output near them may be too large to hear even if another occupant talks and may not be able to talk. In this case, if the audio volume is lowered, conversation becomes possible, but the music becomes difficult to hear this time. In view of the above, it is an object of the present invention to provide an in-vehicle audio device that allows a conversation to be performed smoothly even while listening to audio. In the present invention, a microphone for picking up the voice of an occupant for each seat, an utterance of the occupant and identification means for identifying which occupant of the seat uttered the object are provided. And synthesizing means for, when an utterance of a certain occupant is identified by the identification means, outputting a voice signal of the occupant who is speaking to an audio signal and outputting the signal from a speaker near the occupant other than the occupant who is speaking. Is achieved by According to the present invention, the voice of the occupant for each seat is picked up, the utterance of the occupant and the occupant of the seat that has spoken are identified, and the voice signal of the occupant who is speaking is converted to an audio signal. And output from speakers near occupants other than the occupant who is speaking. As a result, the occupant other than the user who is not speaking can hear the uttered voice from the nearby speaker, so that the conversation can be smoothly performed without lowering the audio volume even while listening to the audio. Does not decrease, so that each occupant can fully enjoy the music, whether or not they are in a conversation. FIG. 1 is an overall configuration diagram of a vehicle-mounted audio device according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a head unit, which in the present embodiment outputs digital audio signals of left and right two channels reproduced from a digital audio source such as a CD. 2a, 2b
Is a volume circuit (VO
L), the volume is increased or decreased in units of 1 dB, for example, in response to volume control by a control unit described later. Volume circuit 2
a and 2b adjust the volume in the digital domain. Reference numeral 3 denotes an operation unit for performing a volume changing operation and the like, and 4 denotes a volume data variable in accordance with the volume changing operation of the operation unit.
a, 2b and set to the volume indicated by the volume data. The adders 5a and 5b are provided after the output side of the volume circuit 2a is branched into two systems.
d is an adder provided after the output side of the volume circuit 2a is branched into two systems, 6a to 6d are D / A converters individually provided on the output side of each adder, and 7a to 7d are each D / A converters.
A power amplifier (AMP) provided on the output side of the A converter,
8a is a front L provided on the output side of the power amplifier 7a.
A channel speaker, 8b is a rear L channel speaker provided on the output side of the power amplifier 7b, 8c is a front R channel speaker provided on the output side of the power amplifier 7c, and 8d is provided on an output side of the power amplifier 7d. The speaker of the rear R channel is located at a predetermined position in the front and rear of the vehicle 9 as shown in the lower right of FIG.
The vehicle 9 is a four-seater, and the occupants for each seat are A to D.
To distinguish. The microphones 10a to 10d are individually installed in front of the occupants and have microphones having sharp directivity for individually catching the utterances of the occupants A to D. Amplifying microphone amplifier, 12a-
12d is an A for individually A / D converting each microphone amplifier output.
/ D converters, 13a to 13d are individually provided on the output side of each A / D converter and include 300 Hz including a road noise component.
An HPF that cuts the following: Reference numeral 14 denotes the output of the head unit and each HPF
Is an identification unit for identifying the utterance of the occupant and the occupant of which seat uttered from the output of the occupant, and is specifically configured as shown in FIG. In FIG. 2, reference numerals 15a and 15b denote HPFs for cutting 300 Hz or less for each channel.
13a to 13d are provided. 16a-1
Reference numeral 6d denotes a correlation degree inspection unit for inspecting the degree of correlation between the microphone input predicted from the output of the head unit 1 and the actual microphone input for each microphone. Correlation degree inspection units 16a to 16
d has the same configuration. Among them, 16a will be described. 17a is the L output from the head unit 1.
A delay circuit (DL) for delaying the time required for the channel audio signal to reach the microphone 10a via the speaker 8a, and a delay circuit 17b for transmitting the L channel audio signal output from the head unit 1 to the microphone 10a via the speaker 8b A delay circuit 17c for delaying by the time required to arrive, 17c is a delay circuit for delaying by the time required for the R channel audio signal output from the head unit 1 to reach the microphone 10a via the speaker 8c, 17d is This is a delay circuit that delays the R channel audio signal output from the head unit 1 by the time required until it reaches the microphone 10a via the speaker 8d. Reference numerals 18a to 18d denote delay circuits 17a to 17d
A level adjustment circuit for reducing the level of each output of the microphone 10a in inverse proportion to the square of the distance between the speakers 8a to 8d and the microphone 10a. 19 adds the outputs of the level adjustment circuits 18a to 18d, and The adders 20 and 21 are for generating a microphone input signal. Each of the adders 20 and 21 is a cascaded two-stage latch circuit that performs a latch operation on a predicted microphone input signal based on a sample clock. The previous sample data is output from the circuit 21. Reference numeral 22 denotes a comparison circuit, which is based on the previous sample data latched by the latch circuit 21 as shown in FIG.
When the current sample data latched by the above is the same or larger, "1" is output, and when the current sample data is smaller, "0" is output. Thus, when the predicted microphone input signal tends to increase, the comparison circuit 22 outputs “1” for each sample clock. Conversely, when the predicted microphone input signal tends to decrease, the comparison circuit 22 outputs the comparison circuit for each sample clock. 22
Outputs “0”. Reference numerals 23 and 24 denote latch circuits each having a two-stage configuration in which a latch operation is performed on an actual microphone input signal (output signal of the HPF 13a) based on a sample clock. The latch circuit 23 outputs the current sample data. The previous sample data is output from the latch circuit 24. 25 is a comparison circuit, as shown in FIG.
Outputs "1" when the current sample data latched by the latch circuit 23 is the same or larger with respect to the previous sample data latched by the latch circuit 24, and outputs "0" when the current sample data is small. I do. Thus, when the actual microphone input signal tends to increase, the comparison circuit 25 outputs “1” for each sample clock, and conversely, when the actual microphone input signal tends to decrease, the comparison circuit 25 outputs “1”. The comparison circuit 22 outputs “0”. Reference numeral 26 denotes the output of the comparison circuit 22 and the comparison circuit 25
And a comparison circuit that outputs “1” when they match and outputs “0” when they do not match.
Reference numeral 7 denotes a counter that counts the number of times that the output of the comparison circuit 27 becomes “0” based on the sample clock. When a predetermined period (for example, 10,000 samples) elapses after the count value is reduced to zero at a certain timing. , And outputs the count value to a determination unit, which will be described later, and restarts counting with the count value set to zero again. When the counter 27 outputs the count value, if the count value is small, the microphone 10a
Indicates that the degree of correlation between the predicted microphone input signal and the actual microphone input signal is large, and when the count value is large, it indicates that the degree of correlation is small. If the occupant A is not speaking, the correlation should be large, and if the occupant A is speaking, the correlation should be small. Therefore, the count value is set to a predetermined reference value (for example, the counting period of the counter 27 is set to 1). By comparing with a reference value of 5000 for 10,000 samples), it is possible to determine whether or not the occupant A speaks (see FIG. 3 (2)). The correlation degree inspection unit 16a is configured as described above with respect to the microphone 10a.
Regarding the microphones 10b to 10d also for b to 16d,
The counter is configured in the same manner as the correlation degree inspection unit 16a, and each of the counters outputs a count value indicating the degree of correlation between the predicted microphone input signal and the actual microphone input signal every time a predetermined period elapses. 28 inputs the count value of the counter from each of the correlation degree inspection units 16a to 16d,
The determination unit determines which seat is occupied when an utterance is made. Specifically, the count values of the counters input from the correlation degree inspection units 16a to 16d are individually compared with a predetermined reference value, and when any of them is below the reference value, it is determined that no one is speaking, When any one exceeds the reference value, for example, when the correlation degree inspection unit 16a exceeds the reference value, it is determined that the corresponding occupant A is speaking. Young
At the same time, when the plurality of count values exceed the reference value, it is determined that one occupant corresponding to the correlation degree inspection unit 16a having the largest count value is speaking. The determination result is output to the synthesizing unit 29 described later. Returning to FIG. 1, reference numeral 29 denotes a speaker based on the identification result of the identification unit 14 (determination result by the determination unit 28), and when there is a speaker, transmits the voice signal to each speaker near the occupant other than the speaker. Is a synthesizing unit for outputting a zero signal data corresponding to a silence signal, and 31 is an adder 5a.
Has four outputs corresponding to .about.5d, and based on the identification result input from the identification unit 14, when it is determined that no speaker is present, all four outputs are set to zero signal data,
When it is determined that the occupant A is speaking, the adder 5b
5d, the input from the HPF 13a is output, and the adder 5a outputs zero signal data. When it is determined that the occupant B is speaking, the adders 5a, 5c,
The input from the HPF 13b is output to 5d, and the zero signal data is output to the adder 5b. When it is determined that the occupant C is speaking, the adders 5a, 5b, 5
For d, the input from the HPF 13c is output, and for the adder 5c, zero signal data is output. When it is determined that the occupant D is speaking, the input from the HPF 13d is output to the adders 5a to 5c, and the zero signal data is output to the adder 5d. Reference numerals 32a to 32d denote a selection output unit and each adder 5.
A volume circuit interposed between a to 5d, which receives volume data from the control unit 4 and adjusts the volume to a volume corresponding to the volume data or a volume larger by a certain amount (for example, 4 dB) than the volume data. I do.
The combining unit 2 includes adders 5a to 5d, a zero signal data generation unit 30, a selection output unit 31, and volume circuits 32a to 32d.
9 are configured. Next, the operation of the above embodiment will be briefly described. While listening to music reproduced from the digital audio source at a certain volume, if no one is speaking, any of the count values output from the counters of the correlation degree inspection units 16a to 16d of the identification unit 14 are all Below the reference value,
The determination unit 28 outputs the determination result that no one is speaking to the selection output unit 31 of the synthesis unit 29. At this time, since the selection output unit 31 outputs the zero signal data to the adders 5a to 5d, only the music from the audio source is output from the speakers 8a to 8d. Therefore, each occupant can fully enjoy the music. Here, for example, when the occupant A speaks to talk to the occupant D, the count value output from the counter 27 of the correlation degree inspection unit 16a of the identification unit 14 exceeds the reference value, and the judgment unit 28 determines that the occupant A has spoken,
The determination result is output to the selection output unit 31. Then, the selection output unit 31 outputs an input from the HPF 13a to the adders 5b to 5d, and outputs zero signal data to the adder 5a. Therefore, the voice of the occupant A is output together with the music from the speakers 8b to 8d, so that the occupants BD can hear the voice of the occupant A while listening to the music. Next, when the occupant D who confirms the call from the occupant A utters the answer, the count value output from the counter of the correlation degree inspection unit 16d of the identification unit 14 exceeds the reference value, and the determination unit 2
8 determines that the occupant D has spoken, and outputs the determination result to the selection output unit 31. Then, the selection output section 31 outputs the adder 5a.
5c, the input from the HPF 13d is output, and the adder 5d outputs zero signal data. Therefore,
Since the sound of the occupant D is output together with the music from the speakers 8a to 8c, the occupants A to C can hear the voice of the occupant D while listening to the music. Hereinafter, similarly, the occupants A and D can have a conversation while listening to music, and the other occupants B and C can enjoy the music while listening to the conversation between A and D. According to this embodiment, the occupant who is not speaking can hear the uttered voice from a nearby speaker, so that even during audio listening, the conversation can be smoothly performed without lowering the audio volume. Can also
Since the volume of the audio is not reduced, each occupant can fully enjoy the music, whether or not they are in a conversation. In the above embodiment, the HPF 1
After rectifying and smoothing the outputs of 3a to 13d, the identification unit 14
To the correlation degree inspection units 16a to 16d,
After the outputs of the HPFs 15a and 15b are individually rectified and smoothed in the identification unit 14, each of the correlation degree inspection units 16a to 16a-1
6d. The determination unit 28
Previously output the determination result of the content in which the speaker does not exist, but when outputting the determination result of the content in which the speaker exists at a certain point in time, the output is held for a certain period of time, and After the lapse of time, the determination may be made again. Conversely, although the determination result of the content where the speaker is present is output, when it is determined that the speaker no longer exists at a certain point in time, when the state where the speaker does not exist continues for a certain period of time, For the first time, a determination result of a content in which no speaker exists may be output. Further, a BPF for limiting the pass band to within 300 Hz to 3 kHz may be provided on each output side of the selection output unit 31. Further, the level adjustment circuits 18a to 1 in each of the correlation degree inspection units 16a to 16d of the identification unit 14
In the case of 8d, the level may be adjusted in consideration of not only the distance between the microphone and each speaker but also the directivity of the microphone. The output of the head unit 1 is set to H
Through the PFs 15a and 15b, the correlation inspection units 16a to 16
Instead of inputting to d, the outputs of the adders 5a to 5d may be individually passed through the HPF and then input to the delay circuits 17a to 17d of the correlation degree inspection unit 16. Further, the identification section may be modified as shown in FIG. In FIG. 4, reference numerals 40a and 40b denote HPFs provided on the output side of the volume circuits 2a and 2b in FIG.
Cuts road noise below 300Hz. 41a-41
Reference numeral d denotes a reference level generator provided separately from the microphones 10a to 10d. The reference level generator obtains the level of the predicted microphone input signal and generates a reference level that is higher than the level by a certain level. Since the reference level generation units 41a to 41d have the same configuration, the reference level generation unit 41a will be described. Among them, reference numeral 42a indicates only the time required for the L-channel audio signal to reach the microphone 10a via the speaker 8a. The delay circuit 42b delays the L-channel audio signal through the microphone 10a through the speaker 8b.
42c is a delay circuit for delaying by the time required until the R channel audio signal
Reference numeral 42d denotes a delay circuit that delays by an amount of time required for the R-channel audio signal to reach the microphone 10a via the speaker 8d. Reference numerals 43a to 43d denote delay circuits 42a to 42d.
43a is a level adjustment circuit for individually adjusting the level of each output, and 43a adjusts its own output level for the L channel audio signal to be the same as the level of the output component of the speaker 8a included in the output of the HPF 13a,
43b is a speaker 8b whose output level for the L channel audio signal is included in the output of the HPF 13b.
43c.
Is adjusted so that its own output level with respect to the R channel audio signal is the same as the level of the output component of the speaker 8c included in the output of the HPF 13c.
The adjustment is performed so that the level of the output component of the speaker 8d included in the output of the PF 13d becomes the same. An adder 44 adds the outputs of the level adjustment circuits 43a to 43d to create a predicted microphone input signal for the microphone 10a, and 45 performs rectification and smoothing on the adder output to perform the level of the predicted microphone input signal. , A reference level generating circuit for generating a reference level signal raised by a certain level (for example, 8 dB) with respect to the output of the rectifying / smoothing circuit 45. The reference level signal will be described later. Output to the judgment unit. The other reference level generating units 41b to 41d also use the microphones 10b to 10d.
For d, the reference level generator 4 for the microphone 10a
It is configured similarly to 1a. 47a to 47d are HPFs 13a to 13d
Rectifier / smoothing circuit that individually rectifies and smoothes the outputs of
Reference numeral 8 compares a reference level signal input from each of the reference level generators 41a to 41d with an actual microphone input signal level input from the rectifier / smoothing circuits 47a to 47d, and determines whether or not the occupant speaks and the occupant of any seat. Is a determination unit that determines whether or not has spoken. Specifically, for the microphone 10a, the actual microphone input signal level input from the rectifying / smoothing circuit 47a is compared with the reference level input from the reference level generator 41a, and if the actual microphone input signal level is equal to the reference level. Is smaller than the threshold, it is determined that the occupant A is not speaking, and conversely, if the actual microphone input signal level is higher than the reference level, it is determined that the occupant A is speaking. Similarly, for the microphone 10b, the actual microphone input signal level input from the rectifying / smoothing circuit 47b is compared with the reference level input from the reference level generator 41b, and if the actual microphone input signal level falls below the reference level. When it is determined that the occupant B is not speaking, conversely, when the actual microphone input signal level is higher than the reference level, it is determined that the occupant B is speaking,
For the microphone 10c, the actual microphone input signal level input from the rectifier / smoothing circuit 47c is used as the reference level generator 4.
1c, and if the actual microphone input signal level is lower than the reference level, it is determined that the occupant C is not speaking, and conversely, the actual microphone input signal level is lower than the reference level. If the reference level is higher than the reference level, it is determined that the occupant C is speaking, and the actual microphone input signal level input from the rectification / smoothing circuit 47d for the microphone 10d is compared with the reference level input from the reference level generation unit 41d. When the actual microphone input signal level is lower than the reference level, it is determined that the occupant D is not speaking, and when the actual microphone input signal level is higher than the reference level. Determines that the occupant D is speaking. When the actual microphone input level is lower than the corresponding reference level for any of the microphones, a determination result indicating that there is no speaker is output, and the actual microphone input level corresponds to only one microphone. When the reference level is higher than the reference level, a judgment result indicating that the corresponding occupant is speaking is output, and when the actual microphone input level is higher than the corresponding reference level for a plurality of microphones at the same time, the corresponding result is output. Among them, a determination result that one occupant corresponding to the microphone having the largest difference between the microphone input level and the reference level is speaking is output. The presence / absence of speech and the occupant of which seat is speaking can also be identified by the identification unit configured as shown in FIG. It should be noted that also in the modification of FIG.
8 has output the determination result of the content in which the speaker does not exist until then, when the determination result of the content in which the speaker exists at a certain point in time is output, the output is held for a certain period of time, After a certain period of time, the determination may be made again. Conversely, although the determination result of the content where the speaker is present is output, when it is determined that the speaker no longer exists at a certain point in time, when the state where the speaker does not exist continues for a certain period of time, For the first time, a determination result of a content in which no speaker exists may be output. Also, the volume circuit 2
Instead of individually inputting the outputs of a and 2b to the respective reference level generators 41a to 41d through the HPFs 15a and 15b, the outputs of the adders 5a to 5d are individually passed through the HPF and then output to the respective reference level generators 41a to 41d. It may be input to each of the delay circuits 42a to 42d of 41d. As described above, according to the present invention, the microphone for picking up the voice of the occupant for each seat, the utterance of the occupant and the identification means for identifying the occupant of the seat which uttered the speech, When the utterance of the occupant is identified,
A synthesizing means for outputting from a speaker near the occupant other than the occupant who is speaking while synthesizing with the audio signal is provided. Then, the voice signal of the occupant who is speaking is output from a speaker near the occupant other than the occupant who is speaking while synthesizing the audio signal with the audio signal. Because you can listen from the speaker, you can have a smooth conversation without lowering the audio volume even while listening to audio, and since the audio volume does not decrease, regardless of whether or not you are in a conversation Each occupant can fully enjoy the music.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall configuration diagram of a vehicle-mounted audio device according to an embodiment of the present invention. FIG. 2 is a specific configuration diagram of an identification unit in FIG. 1; FIG. 3 is an explanatory diagram of a correlation degree inspection method of a correlation degree inspection unit in FIG. 2; FIG. 4 is a configuration diagram of a modification of the identification unit. [Description of Signs] 1 Head units 8a to 8d Speakers 10a to 10d Microphone 14 Identification unit 29 Synthesis unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-38961 (JP, A) JP-A-60-161233 (JP, A) JP-A-63-177604 (JP, A) JP-A-1- 133454 (JP, A) JP-A-1-278160 (JP, A) JP-A-2-312349 (JP, A) JP-A-3-61137 (JP, A) JP-A-5-10103 (JP, U) Japanese Utility Model Showa 56-6012 (JP, U) Japanese Utility Model Showa 58-95347 (JP, U) Japanese Utility Model Showa 61-60544 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 31/00 529 G11B 31/00 519 B60R 11/02 G11B 20/02 H04R 3/00 310

Claims (1)

(57) [Claims 1] An in-vehicle audio device for amplifying an audio signal obtained from an audio source and outputting the amplified audio signal from speakers installed at a plurality of locations in a vehicle cabin. A microphone that picks up the voice of the occupant; identification means for identifying the occupant's utterance and the occupant of the seat that uttered the speech; Synthesizing means for outputting from a speaker near an occupant other than the occupant who is speaking while synthesizing with an audio signal;