JPH07177595A - Sound input device - Google Patents

Abstract

PURPOSE:To allow the user to hear a desired sound in an excellent way by controlling the directivity of a microphone. CONSTITUTION:Plural output signals from an omnidirectinal microphone group 4 are delayed respectively by a delay section 5 and the delayed signals are added by an adder 82. When a switch 30 is depressed, a CPU 90 gives an instruction to a delay control section 80, which reads a delay time coefficient representing a specific directivity pattern from a coefficient storage section 81 to control a delay time of the delay section 5. A timer 12 transmits a time interval for switching the directivity pattern of microphones to the CPU 90. When the witch 30 is detouched, the CPU 90 allows the delay control section 80 to keep the present state and the directivity of the microphones is fixed. Thus, a sound desired by the user is freely selected at any time and the sound input device offering ease of hearing with high articulation is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound input device in the field of sound signal processing.

[0002]

2. Description of the Related Art A conventional sound input device will be described with reference to the drawings. FIG. 14 shows the basic configuration of a conventional sound input device.
Reference numeral 100 is a microphone that converts an acoustic signal transmitted in the air into an electric signal, 101 is an amplifier that amplifies an electric signal output from the microphone, and 102 is an earphone that converts the electric signal output from the amplifier 101 into an acoustic signal.

In the conventional acoustic input device configured as described above, the sound wave reaching the microphone 100 is converted into an electric signal according to the characteristics of the microphone 100.

[0004]

However, in the above structure, there is only one microphone 100 through which the sound wave reaches. If the microphone 100 is omnidirectional,
Unwanted sound other than voice is also converted into an electrical signal and amplified by the amplifier 101, and is output from the earphone 102 as an unpleasant sound with poor clarity. Also, the microphone 1
When 00 is a directional microphone, it has the highest sensitivity to the sound coming from a certain direction, so that only the sound in the limited direction is amplified and heard. Therefore, when the position of the speaker changes, the microphone 10 is moved from the optimum directivity direction.
There was a problem that the directivity of 0 was shifted and the sound different from the desired sound was amplified most.

In view of the above points, the present invention has an object to provide an acoustic input device in which desired sound or voice can be heard well.

[0006]

Means for Solving the Problems A plurality of directional microphones, a selection means for selecting and outputting only one of a plurality of input signals, an address generation means for generating an address assigned to each microphone, and a search start. , A switch for notifying a stop, a reset signal generating means for outputting a reset signal in response to the switch, a stop signal generating means for outputting a stop signal in response to the switch, and a timer for counting time .

[0007]

With the above construction, the directivity of the microphone can be freely changed, and the desired acoustic signal can be obtained by selecting the directivity desired by the user.

[0008]

1 is a block diagram of a sound input device according to a first embodiment of the present invention. In FIG. 1, 1 is a microphone group in which a plurality of directional microphones are arranged in an annular shape, 2 is an amplifier for amplifying an electric signal output from a selector 10, and 3 is an electric signal output from the amplifier 2 is converted into an acoustic signal. Earphones 10 and 10 are address generation units 1
A selector that selects one of a plurality of electric signals output from the microphone group 1 based on the address output by 1 and transmits it to the amplifier 2, 11 is an address generation unit, and is an address assigned to each microphone. Is generated and transmitted to the selector 10. Reference numeral 12 is a timer, which outputs a pulse at regular time intervals to update the address. Reference numeral 20 denotes a reset signal generator, which outputs a reset signal when the switch 30 is pressed to reset the address generator 11 and the timer 12. Reference numeral 21 denotes a stop signal generator, which outputs a stop signal when the switch 30 is released, stops the timer 12 and causes the address generator 11 to hold the current address. Reference numeral 30 is a switch for outputting signals for starting and stopping the search of the microphone, and 31 is a pull-up resistor.

The operation of the sound input device of this embodiment having the above-described structure will be described below. FIG. 2 is a timing chart of each signal generator. When the switch 30 is pressed, the reset signal generator 20 generates a reset signal, which is a signal to start the search of the microphone, and resets the address generator 11 and the timer 12. When the timer 12 is reset, it starts operating and generates a pulse at regular time intervals. The address generator 11 is initialized immediately after resetting and outputs a predetermined address.
Each time a pulse is input from the timer 12, it is updated to the next address. The movement of the address is shown in FIG. These addresses are the microphones M1, M2, ... of the microphone group 1.
.., Mn, and the address next to the last address has a ring type address that returns to the first address, and can be easily configured using a cycle counter. Next, the selector 10 selects the microphone assigned to the address output from the address generation unit 11 from the microphone group 1 and outputs the microphone signal to the amplifier 2. The amplifier 2 amplifies this signal and the earphone 3
Communicate to. The earphone 3 outputs the electric signal output from the amplifier 2 as an acoustic signal. Finally, when the switch 30 is released, the stop signal generator 21 generates a stop signal, which is a signal to stop the search of the microphone, and the timer 12 outputs the stop signal.
To stop. The address generator 11 holds and outputs the current address because there is no pulse input from the timer 12.

As described above, according to this embodiment, a microphone group 1 in which a plurality of directional microphones are arranged in a ring shape
A selector 10 that selects one microphone from a plurality of microphones based on the address output from the address generation unit 11 and outputs the selected microphone to the amplifier 2, and an address generation unit 11 that outputs the address assigned to each microphone. By providing the reset signal generating section 20 for outputting the search start signal of the microphone by the switch 30 and the stop signal generating section 21 for outputting the search stop signal, the user can switch when the sound is difficult to hear. You can start the microphone search by pressing and stop the microphone search by releasing the switch when you hear the sound you want best. Therefore, it is possible to configure a sound input device with high intelligibility that allows the user to freely select a desired sound at any time.

FIG. 4 is a block diagram showing a sound input device according to the second embodiment of the present invention. In FIG. 4, 1
Is a microphone group in which n directional microphones are annularly arranged, 2 is an amplifier for amplifying the electric signal output from the selector 5, 3 is an earphone for converting the electric signal output from the amplifier 2 into an acoustic signal, 5 Is the maximum level detector 4
A selector 10 that selects an input microphone based on the address value transmitted from 1 and transmits to the amplifier 2 is selected from a plurality of electric signals output from the microphone group 1 based on the address output from the address generation unit 11. A selector 11 for selecting one of the microphones and transmitting it to the A / D converter 40 is an address generator, which generates an address assigned to each microphone and transmits it to the selector 10. Reference numeral 13 is a clock, which outputs a pulse at regular time intervals to start updating the address of the address generator 11 and starting A / D conversion of the A / D converter 40. 40 is an A / D converter, selector 1
Memory 50 by A / D converting the electric signal output from 0
Transfer to. Reference numeral 50 is a memory for temporarily storing the data output from the A / D converter 40. Reference numeral 41 denotes a maximum level detector, which obtains the average level of each microphone from the data stored in the memory, and transfers the maximum microphone address value from the average level to the selector 5.

The operation of the sound input device of this embodiment having the above-described structure will be described below. In FIG. 4, when the power of the acoustic input device is turned on, the clock 13 starts operating and outputs a pulse at regular time intervals. The address generator 11 is initialized when the power is turned on and outputs a predetermined address, but is updated to the next address each time a pulse is input from the clock 13. The movement of the address is shown in FIG. These addresses are assigned to the respective microphones M1, M2, ..., Mn of the microphone group 1 consisting of n microphones, and the address next to the last address has a ring type address returning to the first address. And can be easily configured using a cycle counter. Next, the selector 10 selects the microphone assigned to the address output from the address generation unit 11 from the microphone group 1 and outputs the microphone signal to the A / D converter 40. The amplifier 2 amplifies the signal output from the selector 5 and transmits it to the earphone 3. The earphone 3 outputs the electric signal output from the amplifier 2 as an acoustic signal. The A / D converter 40 also A / D-converts the signal output from the selector 10 to convert it to the memory 5
Transfer to 0. The memory 50 stores the data sent from the A / D converter 40. Here, the flow chart of the selector output signal of FIG. 5 and the data address in the memory of FIG. 6 will be used for explanation. In FIG. 4, when one clock pulse is generated, the address of the address generator 11 is updated by one and the microphone selected by the selector 10 is changed by one. Therefore, the microphone selected changes for each clock pulse, and the data flow becomes as shown in FIG. The signal selected by the selector 10 is digitized by the A / D converter 40.
Are sequentially stored in the memory as follows. Therefore, in the case of n microphones, the data of the same microphone is stored in the memory every n−1, and the sampling frequency for the same microphone is 1 / n of the clock frequency. The maximum level detector 41 calculates the average level of each microphone from the data stored in the memory 50,
The address value of the microphone, which is the maximum value, is transmitted to the selector 5.

As described above, according to this embodiment, the microphone group 1 in which a plurality of directional microphones are annularly arranged
A selector 10 that selects one microphone from a plurality of microphones based on the address output from the address generation unit 11 and outputs the selected microphone to the amplifier 2, and an address generation unit 11 that outputs the address assigned to each microphone. , A / D converter 40, memory 50 for storing data, and an average level of each microphone, and a maximum level detector 41 for transmitting the maximum microphone address value to the address generation unit 11 from the average level. By providing, the microphone with the best directional direction is always selected. Therefore, the sound with the highest level is always taken as the target signal and the directivity of the microphone is selected, so that the user can obtain a good sound with a good signal-to-noise ratio.

FIG. 7 is a block diagram of a sound input device according to the third embodiment of the present invention. In FIG. 7, 1
Is a microphone group in which n directional microphones are annularly arranged, 2 is an amplifier for amplifying an electric signal output from the selector 10, 3 is an earphone for converting an electric signal output from the amplifier 2 into an acoustic signal, 10 Is a selector that selects one of a plurality of electric signals output from the microphone group 1 based on the address output from the address generation unit 11 and transmits it to the amplifier 2, and 11 is an address generation unit, and The assigned address is generated and transmitted to the selector 10. Reference numeral 13 is a clock, which outputs a pulse at regular time intervals to start updating the address of the address generator 11 and starting A / D conversion of the A / D converter 40. Four
Reference numeral 0 denotes an A / D converter, which A / D converts the electric signal output from the selector 10 and transfers the electric signal to the memory 50. Fifty
Is a memory for temporarily storing the data output from the A / D converter 40. Reference numeral 60 is a power extraction unit that obtains an average power from each data in the memory, and 61 is a pitch extraction unit that obtains a voice pitch frequency from each data in the memory. Reference numeral 70 denotes a determination unit, which transmits to the selector 5 the address of the microphone having the pitch frequency and the maximum average power.

The operation of the sound input device of this embodiment having the above-described structure will be described below. In FIG. 7, when the power of the sound input device is turned on, the clock 13 starts operating and outputs a pulse at regular time intervals. The address generator 11 is initialized when the power is turned on and outputs a predetermined address, but is updated to the next address each time a pulse is input from the clock 13. The movement of the address is shown in FIG. These addresses are assigned to the respective microphones M1, M2, ..., Mn of the microphone group 1 consisting of n microphones, and the address next to the last address has a ring type address returning to the first address. And can be easily configured using a cycle counter. Next, the selector 10 selects the microphone assigned to the address output from the address generation unit 11 from the microphone group 1 and outputs the microphone signal to the A / D converter 40. The amplifier 2 amplifies the signal output from the selector 5 and transmits it to the earphone 3. The earphone 3 outputs the electric signal output from the amplifier 2 as an acoustic signal. The A / D converter 40 also A / D-converts the signal output from the selector 10 to convert it to the memory 5
Transfer to 0. The memory 50 stores the data sent from the A / D converter 40. Here, the flow chart of the selector output signal of FIG. 5 and the data address in the memory of FIG. 6 will be used for explanation. In FIG. 4, when one clock pulse is generated, the address of the address generator 11 is updated by one and the microphone selected by the selector 10 is changed by one. Therefore, the microphone selected changes for each clock pulse, and the data flow becomes as shown in FIG. The signal selected by the selector 10 is digitized by the A / D converter 40.
Are sequentially stored in the memory as follows. Therefore, in the case of n microphones, the data of the same microphone is stored in the memory every n−1, and the sampling frequency for the same microphone is 1 / n of the clock frequency. The power extraction unit 60 obtains the average power for a preset period from each data stored in the memory 50, and transmits it to the determination unit 70. The pitch extraction unit 61 obtains the pitch frequency of the voice from each data stored in the memory 50 and transmits it to the determination unit 70. The determination unit 70 transmits to the selector 5 the address of the microphone having the pitch frequency and the maximum average power, based on the average power transmitted from the power extraction unit 60 and the pitch frequency transmitted from the pitch extraction unit 61.

As described above, according to this embodiment, the microphone group 1 in which a plurality of directional microphones are annularly arranged
Selectors 5 and 10 for selecting and outputting one microphone from a plurality of microphones based on the input address, an address generator 11 for outputting an address assigned to each microphone, and an A / D converter 40
A memory 50 for storing data, and a power extraction unit 6 for obtaining an average power from the data stored in the memory 50.
0, a pitch extraction unit 61 that obtains a voice pitch from the data stored in the memory 50, and a determination unit 70 that outputs the address value of a microphone that has a pitch and has the maximum average power to the selector 5. Therefore, the microphone always has directivity in the direction of the speaker. Therefore, the voice of the speaker is most audible, and the sound coming from a direction different from the speaker is suppressed, so that the user can obtain a good sound in which the voice of the speaker is easily heard.

FIG. 8 is a block diagram of a sound input device according to the fourth embodiment of the present invention. In FIG. 8, 4
Is a microphone group including n omnidirectional microphones, 6 is a delay unit that delays the electric signals output from the microphones by a time determined by the delay control unit 80, and outputs a delay unit 82. An adder 2 that adds the outputs of the books into one output, 2 is an amplifier that amplifies the electric signal output from the adder 82, 3 is an earphone that converts the electric signal output from the amplifier 2 into an acoustic signal, 12
Is a timer, which interrupts the CPU 90 after a certain period of time and notifies that the time has elapsed. Reference numeral 30 is a switch for outputting a signal for starting and stopping the directivity control of the microphone group 4, and 31 is a pull-up resistor. 80
Is a delay control unit, which controls the delay time of each delay unit 6 based on the data transferred from the coefficient storage unit 81.
Reference numeral 81 denotes a coefficient storage unit that stores a coefficient that represents each delay amount corresponding to n microphones, and 90 is a CPU, which detects ON / OFF of the switch 30, timer interrupt control, and is stored in the coefficient storage unit 81. Existing data to the delay control unit 80
Control to transfer to.

The operation of the sound input device of this embodiment having the above-described structure will be described below. In FIG. 8, when the switch 30 is pressed, the CPU 90 starts directivity control of the microphone group 4 and at the same time resets the timer 12. The timer 12 starts counting immediately after resetting and notifies the CPU 90 by interrupting after a lapse of a certain time. In the coefficient storage unit 81, delay time amounts of the respective microphones for determining some directivity patterns of the microphone group 4 are stored in advance as coefficients. When the CPU 90 starts directivity control of the microphone group 4, one set is selected from the coefficients representing several directivity patterns stored in the coefficient storage unit 81 and transferred to the delay control unit 80 as coefficient data. It Delay control unit 8
0 controls each delay time amount in the delay unit 6 based on the coefficient data transferred from the coefficient storage unit 81, and the coefficient storage unit 8
The directivity pattern of the microphone group 4 stored in 1 is realized. Here, the sound coming from the directivity direction of the microphone group 4 is converted into an electric signal by the microphone group 4 and delayed by the delay unit 6 by a predetermined time. This signal is added by the adder 82, then amplified by the amplifier 2, and output as an acoustic signal by the earphone 3. Next, every time a fixed time elapses, a timer interrupt is generated by the timer 12. When the timer interrupt is generated, the CPU 90 selects a directional pattern next to the previous directional pattern from some directional patterns stored in the coefficient storage unit 81 and transfers it to the delay control unit 80. The delay control unit 80 controls each delay time amount in the delay unit 6 based on the new coefficient data transferred from the coefficient storage unit 81, and the coefficient storage unit 8
The directivity pattern of the four microphone groups stored in the unit 1 is realized. When the switch 30 is finally released, the CPU
Stops the directivity control of the microphone group 4. The delay control unit 80 holds the current state and the directivity of the microphone group 4 is fixed.

As described above, according to the present embodiment, the microphone group 4 including a plurality of omnidirectional microphones and the electric signals output from the respective microphones are delayed by the delay control unit 80 and then output. The delay unit 6, an adder 82 that adds the n outputs from the delay unit 6 into one output, an amplifier that amplifies the electrical signal output from the adder 82, and an electrical signal output from the amplifier 2. To an acoustic signal, a timer 12 that interrupts the CPU 90 when a certain time has elapsed and notifies that the time has elapsed, and a switch for outputting signals for starting and stopping the directivity control of the microphone group 4. 30 and the delay unit 6 based on the data transferred from the coefficient storage unit 81.
Delay control section 80 for controlling each delay time, coefficient storage section 81 for storing a coefficient representing each delay time amount corresponding to n microphones, ON / OFF detection of switch 30, timer interrupt control , C for controlling transfer of data stored in the coefficient storage unit 81 to the delay control unit 80
By providing the PU90, the user presses the switch to start directivity control of the microphone group when it is difficult to hear the sound, and releases the switch when the desired sound is best heard, thereby fixing the directivity of the microphone group. can do. For this reason, the sound desired by the user can be freely selected at any time, and a sound input device that is easy to hear and has high intelligibility can be configured.

FIG. 9 is a block diagram showing the configuration of the sound input device according to the fifth embodiment of the present invention. In FIG. 9, 4
Is a microphone group composed of n omnidirectional microphones, 6 and 6a are delay units that delay electric signals output from the microphones by a time determined by delay control units 80 and 80a, and 82 and 82a are An adder that adds the n outputs from the delay unit 6 into one output,
2 is an amplifier that amplifies the electric signal output from the adder 82, 3 is an earphone that converts the electric signal output from the amplifier 2 into an acoustic signal, and 40 is an A / D conversion of the electric signal output from the adder 82 A / D converter, 50 is a memory for storing the A / D converted data, 41 is a maximum level detector, and an average level is obtained from the respective data stored in the memory. Information representing the maximum directivity pattern is transmitted to the CPU 90. 7 is the CPU 90
The delay unit 12 for delaying the A / D conversion start signal output from the A / D converter 40 and transmitting it to the A / D converter 40 is a timer, and when a certain time has elapsed, it interrupts the CPU 90 to notify that the time has elapsed. Reference numerals 80 and 80a denote delay control units, which control the delay times of the delay units 6 and 6a based on the data transferred from the coefficient storage units 81 and 81a. 8
Reference numerals 1 and 81a denote coefficient storage units that store coefficients representing respective delay amounts corresponding to n microphones. 90 is CP
U, timer interrupt control, coefficient storage 81, 81a
The control for transferring the internally stored data to the delay control units 80 and 80a and the output of the A / D conversion start signal are performed.

The operation of the sound input device of this embodiment having the above-described structure will be described below. In FIG. 9, when the power of the sound input device is turned on, the CPU 90 starts its operation and starts the directivity control of the microphone group 4 and at the same time resets the timer 12. The timer 12 starts counting immediately after resetting, and after a certain time elapses, the CP
Interrupt and notify U90. Coefficient storage unit 81, 81
In a, a delay time amount of each microphone for determining some directivity patterns of the microphone group 4 is stored in advance as a coefficient. When the CPU 90 starts directivity control of the microphone group 4, the coefficient storage unit 8
One set is selected from the coefficients representing several directivity patterns stored in Nos. 1 and 81a and transferred to the delay control units 80 and 80a as coefficient data. Delay control unit 80,
Reference numeral 80a controls the amount of delay time in each of the delay units 6 and 6a based on the coefficient data transferred from the coefficient storage units 81 and 81a, and directivity of the microphone group 4 stored in the coefficient storage units 81 and 81a. Realize the pattern. Here, the sound coming from the directivity direction of the microphone group 4 is converted into an electric signal by the microphone group 4 and delayed by a predetermined time by the delay units 6 and 6a. The signals output from the delay units 6 and 6a are added by adders 82 and 82a, respectively. The signal output from the adder 82a is amplified by the amplifier 2 and output as an acoustic signal by the earphone 3. The signal output from the adder 82 is input to the A / D converter 40. When the A / D conversion start signal is input from the delay unit 7, the A / D converter 40 starts A / D conversion and stores data in the memory 50. The maximum level detector 41 is a memory 50
The average level is obtained from the data of the respective directional patterns stored therein, and the information indicating the maximum directional pattern among them is transmitted to the CPU 90. When the directivity pattern at the maximum level is transmitted from the maximum level detector 41, the CPU 90 transmits the coefficient realizing the directivity pattern from the coefficient storage unit 81a to the delay control unit 80a. The delay control unit 80a controls the delay time of each of the delay units 6a to realize the directivity pattern at the maximum level. Next, every time a fixed time elapses, a timer interrupt is generated by the timer 12. When the timer interrupt is generated, the CPU 90 selects a directional pattern next to the previous directional pattern from some directional patterns stored in the coefficient storage unit 81 and transfers it to the delay control unit 80. The delay control unit 80 controls each delay time amount in the delay unit 6 based on the new coefficient data transferred from the coefficient storage unit 81, and the coefficient storage unit 81
The directivity pattern of the four microphone groups stored in the inside is realized. FIG. 10 is a diagram showing an example of the arrangement of microphones and directivity patterns. In this case, the distance between the microphones at both ends is αcm, and the directivity pattern is a, b,
7 are c, ..., F, and g. Therefore, if the speed of sound transmitted in the air is βcm / sec, the maximum delay time is α / βsec.
Therefore, the delay time of the delay unit 6 needs to be set to α / β sec or more. Further, the time interval of the timer 12 is the CPU 90
Since it is the time interval of the A / D conversion start signal output by, the time setting of the timer 12 must be set to a time of α / β sec or more. FIG. 11 is an explanatory diagram of the flow of signals output from the adder, and FIG. 12 is an explanatory diagram of data addresses stored in the memory. The directivity pattern changes every time a timer interrupt is generated by the timer 12, and the data flow is a, b, c, ..., F, g, a, b, c, as shown in FIG.
, F, g, a, b ... and the seven directivity patterns are repeated in order. Therefore, as the data stored in the memory 50, the data of the same directivity pattern is sequentially stored for every seven data as shown in FIG. Therefore, the sampling frequency for the same directivity pattern is β / 7αHz or less. When there are n directivity patterns, the sampling frequency for the same directivity pattern is β / nαHz or less. The sampling frequency β / nα is preferably 2000 Hz or higher because the first formant component of the vowel is 1000 Hz or lower.

As described above, according to the present embodiment, the microphone group 4 including a plurality of omnidirectional microphones and the electric signals output from the microphones are delayed by the time determined by the delay control units 80 and 80a, respectively. And the delay units 6 and 6a for outputting the output, the adders 82 and 82a for adding the n outputs from the delay unit 6 into one output, and the adder 8
2, an A / D converter 40 for A / D converting the electric signal output from the memory 2, and a memory 5 for storing the A / D converted data.
0 and the maximum level detector 41 which calculates the average level from the respective data stored in the memory and transmits the information indicating the directivity pattern at the maximum among them to the CPU 90.
And a delay unit 7 that delays the A / D conversion start signal output from the CPU 90 and transmits it to the A / D converter 40, and a timer 12 that interrupts the CPU 90 after a certain time and notifies that the time has elapsed. And coefficient storage units 81 and 8
A delay control unit 80, 80a for controlling the delay time of each of the delay units 6, 6a based on the data transferred from 1a;
Coefficient storage units 81 and 81a that store coefficients representing delay amounts corresponding to n microphones, timer interrupt control, and data stored in the coefficient storage units 81 and 81a are transferred to the delay control units 80 and 80a. By providing the control for controlling and the CPU 90 for outputting the A / D conversion start signal,
A directional pattern with a high level is always selected. Therefore, the sound with the highest level is always the target signal, and the directivity of the microphone group 4 is selected, so that the user can obtain a good sound with a good signal-to-noise ratio.

FIG. 13 is a block diagram showing a sound input device according to the sixth embodiment of the present invention. In FIG. 13, 4 is a microphone group including n omnidirectional microphones. Reference numerals 6 and 6a denote delay units for delaying the electric signals output from the microphones by a time determined by the delay control units 80 and 80a, and outputting the delay signals 82 and 82, respectively.
a is an adder that adds n outputs from the delay unit 6 into one output, 2 is an amplifier that amplifies the electrical signal output from the adder 82, and 3 is an acoustic signal that outputs the electrical signal output from the amplifier 2. An earphone for converting into a signal, 40 is an A / D converter for A / D converting the electric signal output from the adder 82, 50
Is a memory for storing A / D converted data, and 60 is a CPU 90 which calculates an average power from each data in the memory.
A power extraction unit 61 for transmitting to the CPU 90 is a pitch extraction unit for obtaining the pitch frequency of the voice from the data in the memory and transmitting it to the CPU 90. Reference numeral 7 denotes a delay unit that delays the A / D conversion start signal output from the CPU 90 and transmits the signal to the A / D converter 40. Reference numeral 12 denotes a timer.
An interrupt is sent to 90 to inform that the time has elapsed.
Reference numerals 80 and 80a denote delay control units, which are coefficient storage units 81 and 8
The delay time of each of the delay units 6 and 6a is controlled based on the data transferred from 1a. Reference numerals 81 and 81a denote coefficient storage units that store coefficients representing the respective delay amounts corresponding to the n microphones. Reference numeral 90 denotes a CPU, which has a timer interrupt control, a control for transferring the data stored in the coefficient storage unit 81 to the delay control unit 80, and a pitch frequency.
The coefficient of the directivity pattern having the maximum average power is transferred from the coefficient storage unit 81a to the delay control unit 80a, and the A / D conversion start signal is output.

The operation of the sound input device of this embodiment having the above-described structure will be described below. In FIG. 13, when the power of the sound input device is turned on, the CPU 90 starts its operation and resets the timer 12 at the same time as starting the directivity control of the microphone group 4. The timer 12 starts counting immediately after reset, and C
An interrupt is sent to the PU 90 to notify it. Coefficient storage unit 81, 8
In 1a, delay time amounts of respective microphones for determining some directivity patterns of the microphone group 4 are stored in advance as coefficients. When the CPU 90 starts directivity control of the microphone group 4, the coefficient storage unit 8
One set is selected from the coefficients representing several directivity patterns stored in Nos. 1 and 81a and transferred to the delay control units 80 and 80a as coefficient data. Delay control unit 80,
Reference numeral 80a controls the amount of delay time in each of the delay units 6 and 6a based on the coefficient data transferred from the coefficient storage units 81 and 81a, and directivity of the microphone group 4 stored in the coefficient storage units 81 and 81a. Realize the pattern. Here, the sound coming from the directivity direction of the microphone group 4 is converted into an electric signal by the microphone group 4 and delayed by a predetermined time by the delay units 6 and 6a. The signals output from the delay units 6 and 6a are added by adders 82 and 82a, respectively. The signal output from the adder 82a is amplified by the amplifier 2 and output as an acoustic signal by the earphone 3. The signal output from the adder 82 is input to the A / D converter 40. When the A / D conversion start signal is input from the delay unit 7, the A / D converter 40 starts A / D conversion and stores data in the memory 50. The power extraction unit 60 obtains the average power for a preset period from each data stored in the memory 50 and transmits it to the CPU 90. The pitch extraction unit 61 obtains the pitch frequency of the voice from the data stored in the memory 50 and transmits it to the CPU 90. CPU9
0 is the average power transmitted from the power extraction unit 60 and the pitch frequency transmitted from the pitch extraction unit 61, and the coefficient of the directional pattern having the pitch frequency and the maximum power is controlled from the coefficient storage unit 81a by delay control. It is transmitted to the section 80a. The delay control unit 80a controls the delay time of each of the delay units 6a to realize a directivity pattern in which a pitch exists and maximum power is achieved. Next, every time a fixed time elapses, a timer interrupt is generated by the timer 12. When the timer interrupt is generated, the CPU 90 selects a directional pattern next to the previous directional pattern from some directional patterns stored in the coefficient storage unit 81 and transfers it to the delay control unit 80. The delay control unit 80 controls each delay time amount in the delay unit 6 based on the new coefficient data transferred from the coefficient storage unit 81, and the directivity pattern of the microphone 4 group stored in the coefficient storage unit 81. To realize.
FIG. 10 is a diagram showing an example of the arrangement of microphones and directivity patterns. In this case, the distance between the microphones at both ends is αcm, and the directivity pattern is a, b, c, ..., F,
7 of g. Therefore, the speed of sound transmitted in the air is β
When it is cm / sec, the maximum delay time is α / β sec, and the delay time of the delay unit 6 needs to be set to α / β sec or more.
Further, the time interval of the timer 12 is A output by the CPU 90.
Since the time interval of the / D conversion start signal is reached, the timer 12 must also be set to a time of α / β sec or more. FIG. 11 is an explanatory diagram of a signal flow of an adder output,
FIG. 12 is an explanatory diagram of data addresses stored in the memory. The directivity pattern changes each time a timer interrupt is generated by the timer 12, and the data flow is a, b, c, ..., F, g, a, b, c, ..., f, g, as shown in FIG.
.., and 7 directivity patterns are repeated in order. Therefore, as the data stored in the memory 50, the data of the same directivity pattern is sequentially stored for every seven data as shown in FIG. Therefore, the sampling frequency for the same directivity pattern is β / 7αHz or less. When there are n directivity patterns, the sampling frequency for the same directivity pattern is β / nαHz or less. The sampling frequency β / nα is preferably 2000 Hz or higher because the first formant component of the vowel is 1000 Hz or lower.

As described above, according to the present embodiment, the microphone group 4 including a plurality of omnidirectional microphones and the electric signals output from the respective microphones are delayed by the time determined by the delay control units 80 and 80a, respectively. And the delay units 6 and 6a for outputting the output, the adders 82 and 82a for adding the n outputs from the delay unit 6 into one output, and the adder 8
2, an A / D converter 40 for A / D converting the electric signal output from the memory 2, and a memory 5 for storing the A / D converted data.
0 and the average power is calculated from each data in the memory C
A power extraction unit 60 for transmitting to the PU 90, a pitch extraction unit 61 for obtaining a pitch frequency of voice from data in the memory and transmitting it to the CPU 90, and an A / A output from the CPU 90.
A delay unit 7 that delays the D conversion start signal and transmits it to the A / D converter 40; a timer 12 that interrupts the CPU 90 after a certain period of time and notifies that the time has elapsed;
Delay control units 80 and 80a that control the delay times of the delay units 6 and 6a based on the data transferred from the coefficient storage units 81 and 81a, and coefficients that represent the delay amounts of the n microphones, respectively. Coefficient storage unit 81, 81a for storing
A timer interrupt control, a control for transferring the data stored in the coefficient storage unit 81 to the delay control unit 80, a coefficient of a directivity pattern having a pitch frequency and a maximum average power, Delay control unit 80 from within 81a
By providing the control for transferring to the a and the CPU 90 that outputs the A / D conversion start signal, the microphone group 4 is always oriented toward the speaker. Therefore, the voice of the speaker is most audible, and the sound coming from a direction different from the speaker is suppressed, so that the user can obtain a good sound in which the voice of the speaker is easily heard.

In the first, second and third embodiments, the microphone group 1 has a plurality of directional microphones arranged in an annular shape, but may be arranged in a fan shape. Further, in the second and fifth embodiments, the maximum level detector 41 obtains the maximum value of each average level, but the maximum value of the average amplitude and the maximum value of the average power may be obtained. Further, in the third and sixth embodiments, the power extraction unit 60 obtains the average power of each data stored in the memory, but the average level and the average amplitude may be obtained.

[0027]

According to the present invention, when the user finds it difficult to hear the sound, the user pushes the switch to start the search of the microphone, and when the user can hear the desired sound best, the switch is released to release the microphone. -You can stop. Therefore, it is possible to configure a sound input device with high intelligibility that allows the user to freely select a desired sound at any time. Further, according to the present invention, by providing the pitch extraction unit and the power extraction unit, the microphone is always directed toward the speaker. Therefore, the speaker's voice is most audible and the sound coming from a direction different from that of the speaker is suppressed, so that the user can obtain a good sound in which the speaker's voice is easily heard.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a sound input device according to a first embodiment of the present invention.

FIG. 2 is a timing chart of each part.

FIG. 3 is an explanatory diagram showing movement of addresses assigned to each microphone.

FIG. 4 is a configuration diagram of a sound input device according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a signal flow of a selector output.

FIG. 6 is an explanatory diagram showing data addresses in a memory.

FIG. 7 is a configuration diagram of a sound input device in a third embodiment of the present invention.

FIG. 8 is a configuration diagram of a sound input device in a fourth embodiment of the present invention.

FIG. 9 is a configuration diagram of a sound input device according to a fifth embodiment of the present invention.

FIG. 10 is an explanatory diagram of a microphone arrangement and a directivity pattern.

FIG. 11 is an explanatory diagram of a signal flow of an adder output.

FIG. 12 is an explanatory diagram showing data addresses in a memory.

FIG. 13 is a configuration diagram of a sound input device according to a sixth embodiment of the present invention.

FIG. 14 is a configuration diagram of a conventional sound input device.

[Explanation of symbols]

 1 Microphone Group 2 Amplifier 3 Earphone 4 Microphone Group 5 Selector 6 Delay Unit 6a Delay Unit 7 Delay Unit 10 Selector 11 Address Generator 12 Timer 13 Clock 20 Reset Signal Generator 21 Stop Signal Generator 30 Switch 31 Pullup Resistor 40 A / D converter 41 Maximum level detector 50 Memory 60 Power extraction unit 61 Pitch extraction unit 70 Judgment unit 80 Delay control unit 80a Delay control unit 81 Coefficient storage unit 81a Coefficient storage unit 82 Adder 82a Adder 90 CPU 100 Microphone 101 Amplifier 102 earphone

Claims (7)

[Claims] 1. A plurality of directional microphones, a selection means for selecting and outputting only one from a plurality of input signals, an address generation means for generating an address assigned to each microphone, and a search start / stop notification. A switch, a reset signal generating means for outputting a reset signal in response to the switch, a stop signal generating means for outputting a stop signal in response to the switch, and a timer for measuring time. Sound input device. 2. A plurality of directional microphones, a first selecting means for selecting and outputting only one of the plurality of input signals, and a second selecting means for selecting and outputting only one of the plurality of input signals.
Selection means, address generation means for generating an address assigned to each microphone, A / D conversion means for converting an input signal into digital data, storage means for storing data, and a microphone of maximum level from each data. An acoustic input device comprising maximum level detecting means for detecting 3. A plurality of directional microphones, a first selecting means for selecting and outputting only one of the plurality of input signals, and a second selecting and outputting only one of the plurality of input signals.
Selection means, address generation means for generating an address assigned to each microphone, A / D conversion means for converting an input signal into digital data, storage means for storing data, and average power extracted from each data. A sound input device, comprising: a power extraction unit for extracting the pitch, a pitch extraction unit for extracting a pitch from each data, and a determination unit for selecting one having a pitch and a maximum average power. 4. A plurality of omnidirectional microphones, a delay means for delaying each of a plurality of input signals, an adding means for adding a plurality of input signals, a storage means for storing a delay time as a coefficient, and the delay means. Delay control means for controlling the delay time, a switch for notifying search start and stop, a timer for measuring time, a CPU for controlling the switch, the timer, and the delay control means. Sound input device. 5. A plurality of omnidirectional microphones, a first delay means for delaying each of the plurality of input signals, a second delay means for delaying each of the plurality of input signals, and a plurality of input signals. First adding means, second adding means for adding a plurality of input signals, storage means for storing delay time as a coefficient, first delay control means for controlling the delay time of the delay means, and Second delay control means for controlling the delay time of the delay means, A / D conversion means for converting an input signal into digital data, storage means for storing data, and maximum level directivity detected from each data Maximum level detecting means, a timer for measuring time,
Third delay means for delaying the output signal to the A / D conversion, the maximum level detection means, the A / D conversion means,
An acoustic input device comprising the first and second delay control means and a CPU for controlling the timer. 6. A plurality of omnidirectional microphones, a first delay means for delaying each of the plurality of input signals, a second delay means for delaying each of the plurality of input signals, and a plurality of input signals. First adding means, second adding means for adding a plurality of input signals, storage means for storing delay time as a coefficient, first delay control means for controlling the delay time of the delay means, and Second delay control means for controlling the delay time of the delay means, A / D conversion means for converting an input signal into digital data, storage means for storing data, and power extraction for extracting an average power from each data Means, pitch extracting means for extracting a pitch from each data, a timer for measuring time, a third delay means for delaying an output signal to the A / D conversion, the power extracting means, the An acoustic input device comprising: a pitch extracting means, the A / D converting means, the first and second delay control means, and a CPU for controlling the timer. 7. The delay times of the third delay means are first and second delay times.
7. The sound input device according to claim 5, wherein the delay time is equal to or longer than the delay time determined by the delay unit.