JP2000307484A - Audio signal processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an audio signal processor which enables an announcer who wears an earphone to eliminate the trouble that the voice of the announcer is heard through the earphone after being delayed through a satellite line, etc., when live braodcast is sent to television or radio on the spot. SOLUTION: The audio signal processor 100 converts audio signals S61 and S62 into digital audio signals S71 and S72 by A/D converting means 71 and 72. A delay time detecting means 73 detects the delay time of the audio signal S72 and a removing means 74 generates a removed signal S74 by removing the signal corresponding to the audio signal S71 from the audio signal S72. A sound volume control means 81 generates a variable audio signal S81 by attenuating the audio signal S72 and a sound volume control means 82 generate a variable audio signal S82 by attenuating the removed signal S74; and an adding means 83 generates an addition signal S83 by adding the variable audio signals S81 and S82 together and a D/A converting means 85 converts it into an analog signal S85.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a first audio signal, wherein a second audio signal obtained by delaying a first audio signal by a predetermined time is supplied;
The present invention relates to an audio signal processing device capable of removing a signal corresponding to the audio signal from the second audio signal.

[0002]

2. Description of the Related Art There is a case where a broadcast car is moved near a site, an announcer at the site explains the situation, and the situation at the site is broadcast live on a television or radio. When the sound of the on-site announcer is transmitted from a broadcasting car to a broadcasting station via a satellite line,
An audio signal included in a broadcast wave from a broadcasting station has a delay of about 0.3 to 0.6 seconds from the time when the sound of the announcer is sounded.

[0003] An announcer at the site often gives an explanation of the situation at the site while monitoring the audio signal of the broadcast radio wave with earphones. However, the announcer is 0.3-0.6
It is difficult to speak while monitoring your own voice delayed by about 2 seconds with earphones. For this reason, there is an audio signal processing device that removes a signal corresponding to the first audio signal from the second audio signal in which the first audio signal is delayed. The output signal of the audio signal processing device may be supplied to an announcer earphone.

FIG. 6 is a block diagram showing the configuration of a conventional audio signal processing device. This audio signal processing device 10
Are input terminals 11 and 12, analog / digital conversion means (A / D conversion means) 21 and 22, delay time detection means 23, removal means 24, and digital / analog conversion means (D / A conversion means). 25 and an output terminal 29.

The first input terminal 11 is supplied with a first audio signal S11 composed of an analog signal. The second input terminal 12 is a second audio signal (audio delay signal) S1 which is an analog signal obtained by delaying the first audio signal S11 by a predetermined time.
2 are supplied.

[0006] The first A / D conversion means 21 outputs the audio signal S
11 is supplied, the audio signal S11 is converted from analog to digital to generate a digital audio signal S21, and the audio signal S21 is supplied to the delay time detecting means 23.

[0007] The second A / D conversion means 22 receives the input signal S
The input signal S12 is supplied to the input terminal S12. The input signal S12 is converted from analog to digital to generate an input signal S22 of a digital signal. The input signal S22 is supplied to the delay time detecting means 23 and the removing means 24.

The delay time detecting means 23 comprises first and second delay time detecting means.
The delay time Td is detected based on the audio signals S21 and S22, and a delay time signal S23 indicating the delay time Td is output to the removing unit 24.

The removing means 24 has an echo canceller, and converts the signal corresponding to the first audio signal S21 from the second audio signal S22 to the adaptive filter based on the delay time Td detected by the delay time detecting means 23. A removal signal S24 removed by the processing is generated, and this removal signal S24 is
It is supplied to the A conversion means 25. The removal unit 24 supplies the second audio signal S22 to the D / A conversion unit 25 as the removal signal S24 until the removal process starts.

The D / A converter 25 is supplied with a removal signal S24 composed of a digital signal.
Is converted from digital to analog to generate a removal signal S25 of an analog signal, and the removal signal S25 is output to an output terminal 29.
To supply.

[0011]

SUMMARY OF THE INVENTION An audio signal processing device 10
In the case where the delay time Td is detected, there may be a case where the second audio signal S12 contains a sound signal such as BGM in addition to the sound of the announcer at the site, so that the delay time Td cannot be detected. There is.

Also, a certain amount of calculation time is required from the start of detection of the delay time Td to the start of the removal processing, and the audio signal processing device 10 changes the signal level of the removal signal S24 before and after the start of the removal processing. It cannot be changed. For this reason, when the output signal is supplied to the earphone from the output terminal 29 until the operation time elapses after the on-site announcer starts speaking, when the announcer starts speaking, the announcer's own sound is delayed from the earphone There is a problem that you can hear.

An object of the present invention is to change a signal level of a second audio signal and a removed signal obtained by removing a signal corresponding to the first audio signal from the second audio signal. An object of the present invention is to provide an audio signal processing device that can be added.

[0014]

In an audio signal processing apparatus according to the present invention, a first audio signal and a second audio signal obtained by delaying the first audio signal are supplied to the first audio signal. Is greater than or equal to a predetermined signal level, a delay time detecting means for detecting a delay time of the second audio signal, and the first time signal based on the delay time detected by the delay time detecting means. Removing means for generating a removal signal by removing a signal corresponding to the second audio signal from the second audio signal; and a first means for changing a signal level of the second audio signal.
A first sound volume adjusting means for generating a variable sound signal, a second sound volume adjusting means for generating a second variable sound signal in which a signal level of the removal signal is changed, and the first and second sound signals.
And an adding means for adding the variable audio signal.

[0015] In the audio signal processing device according to the present invention, preferably, the first sound volume adjusting means is configured to output the first variable audio signal when the first audio signal is higher than the predetermined signal level. Is attenuated from the signal level of the second audio signal to zero level or a level near the same, and if the delay time detecting means cannot detect the delay time, the first audio signal is lower than the predetermined signal level. , The first variable audio signal is returned to the signal level of the second audio signal.

In the audio signal processing device according to the present invention, more preferably, the first sound volume adjusting means is configured to output the first variable audio signal when the first audio signal is higher than the predetermined signal level. The signal is attenuated from the signal level of the second audio signal to a signal level lower than the signal level, and further attenuated to a zero level after the start of the removal processing by the removal means, and the second volume adjustment means includes: After the removal process is started by the removal means, the second variable audio signal is increased from zero level to the signal level of the removal signal.

[0017] In the audio signal processing device according to the present invention, more preferably, the first sound volume adjusting means is configured to output the first variable audio signal when the first audio signal is higher than the predetermined signal level. The signal is attenuated from the signal level of the second audio signal to a signal level lower than the signal level, and further attenuated to a zero level after the start of the removal processing by the removal means, and the second volume adjustment means includes: After the first variable audio signal has reached a zero level or a level near the zero level,
The second variable audio signal is increased from a zero level to a signal level of the removal signal.

In the audio signal processing apparatus according to the present invention, more preferably, the first volume adjusting means removes the signal by the removing means when the first audio signal is higher than the predetermined signal level. By the start of the processing, the first variable audio signal is attenuated from the signal level of the second audio signal to zero level or a level near the same, and the second sound volume adjustment means removes the signal by the removal means After the start of the processing, the second variable audio signal is increased from zero level to the signal level of the removal signal.

The delay time detecting means detects a delay time based on the first and second audio signals when the first audio signal is equal to or higher than a predetermined signal level. Thus, when the first audio signal becomes equal to or higher than the predetermined signal level, it is possible to immediately start the delay time detection process.

The first sound volume adjusting means generates a first variable audio signal in which the signal level of a second audio signal (audio delay signal) is changed. The second volume adjusting means generates a second variable audio signal in which the signal level of the removal signal from the removing means is changed. Since the addition means adds the first and second variable audio signals, the audio signal processing device according to the present invention can add the second audio signal and the removal signal by changing the signal level.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of an audio signal processing device according to the present invention.

The audio signal processing apparatus 100 includes input terminals 61 and 62 and analog / digital conversion means (A / D
Conversion means) 71, 72, delay time detection means 73, removal means 74, signal detection means 75, control means 76,
Volume adjusting means 81 and 82, adding means 83, digital / analog converting means (D / A converting means) 85, and output terminal 89 are provided.

The first input terminal 61 is supplied with a first audio signal S61 which is an analog signal. The second input terminal 62 is supplied with a second audio signal S62 which is an analog signal obtained by delaying the audio signal S61 by a predetermined time.

The first A / D converter 71 is supplied with the first audio signal S61, and converts the first audio signal S61 from analog to digital to generate a first audio signal S71 as a digital signal. The first audio signal S71 is supplied to the delay time detecting means 73 and the signal detecting means 75.

The second A / D converter 72 is supplied with the second audio signal S62, and converts the second audio signal S62 from analog to digital to generate a second audio signal S72 as a digital signal. The second audio signal S72 is supplied to the delay time detecting means 73, the removing means 74, and the first volume adjusting means 81.

The signal detection means 75 generates a detection signal S75 when the signal level of the audio signal S71 is equal to or higher than a predetermined signal level, and outputs the detection signal S75 to the delay time detection means 73 and the control means 76. To supply. In addition,
It is assumed that the predetermined signal level is a signal level within a range that the audio signal S71 can take and is set in advance to a signal level larger than noise (noise).

The delay time detecting means 73 includes the signal detecting means 7
5 detects the delay time Td of the second audio signal S72 based on the first and second audio signals S71 and S72, and detects the delay time Td.
The delay time signal S73 indicating d is supplied to the control means 76. Since the delay time detecting means 73 performs a process of detecting the delay time Td based on the detection signal S75, the sound signal S
When the signal level of the signal 71 exceeds the predetermined signal level, the detection process of the delay time Td can be started immediately. The delay time detecting means 73 detects the delay time Td when the audio signal S71 is equal to or higher than the predetermined signal level. It is possible to improve the detection accuracy of Td.

The control means 76 controls the audio signal processing device 100
Is a controller that controls the entire operation of the digital signal processor, and includes a central processing unit (CPU) that performs high-speed signal processing, a ROM and a RAM, and may be configured by, for example, a one-chip microcomputer. )
May be configured. The control means 76 includes a signal detection means 75
Adjustment signals S76a and S7 based on the detection signal S75 from the controller and the delay time signal S73 from the delay time detector 73.
6b, and supplies the adjustment signal S76a to the first volume adjustment unit 81 and supplies the adjustment signal S76b to the second volume adjustment unit 82. Further, the control means 76 determines that the delay time Td
Is supplied to the removing unit 74, and the removing unit 74 starts the removing process.

The removing means 74 receives the second sound signal S7 based on the signal indicating the delay time Td from the control means 76.
2 to generate a removal signal S74 from which a signal corresponding to the first audio signal S71 has been removed, and supplies the removal signal S74 to the second volume adjusting means 82. The removing unit 74 includes, for example, an echo canceller, and outputs the first audio signal S71.
Is removed from the second audio signal S72 by adaptive filter processing.

The first volume control means 81 includes a control means 76.
Generates a first variable audio signal S81 that is controlled by the adjustment signal S76a from the second unit and changes the second audio signal S72, and adds the first variable audio signal S81 to the adding means 83.
To supply. When the first audio signal S71 is equal to or higher than the predetermined signal level, the first volume adjusting means 81 converts the first variable audio signal S81 to, for example, the second audio signal S72.
To a zero level or a level near the zero level. When the delay time detecting means 73 cannot detect the delay time Td, the first sound volume adjusting means 81 outputs the first variable sound signal after the first sound signal S71 falls below the predetermined signal level. S81 is returned to, for example, the signal level of the second audio signal S72 to return to the original state.

The second volume control means 82 includes a control means 76
Is controlled by the adjustment signal S76b from the
No. 4 second variable audio signal S82 having a changed signal level
Is generated, and the second variable audio signal S82 is added to the adding means 8
Supply 3 The second volume adjusting means 82 includes the removing means 7
4, the second variable audio signal S82
Is increased from, for example, the zero level to the signal level of the removal signal S74.

The adding means 83 includes a first volume adjusting means 81
Supplies the first variable audio signal S81, and the second volume adjusting means 82 supplies the second variable audio signal S82. The adding means 83 generates the first and second attenuation signals S
81 and S82 are added to generate an addition signal S83,
This addition signal S83 is supplied to the D / A conversion means 85.

The D / A converter 85 is supplied with the addition signal S83 composed of a digital signal.
83 is converted from digital to analog to generate an addition signal S85 of an analog signal, and this addition signal S85 is supplied to an output terminal 89.

The operation of the audio signal processing apparatus Next, an operation example of the audio signal processing apparatus according to the present invention with reference to FIG. FIG. 2 shows the audio signal processing device 1 of FIG.
12 is a schematic flowchart for explaining the operation of the 00.

First, at step F1, the control means 76
Converts the first variable audio signal S81 into the second audio signal S72.
, And an adjustment signal S76b for initializing the second variable audio signal S82 to a zero level or a level close thereto is generated. Based on the adjustment signal S76a, the first sound volume adjustment unit 81 supplies the first variable audio signal S81 having the signal level of the second audio signal S72 to the addition unit 83. Based on the adjustment signal S76b, the second volume adjustment unit 82 supplies the second variable audio signal S82 having a signal level of zero level or a level near the zero level to the addition unit 83.

In step F2, the control means 76 sets the first
Is determined based on the presence or absence of the supply of the detection signal S75 from the signal detection means 75, whether or not the audio signal S71 is equal to or higher than a predetermined signal level set in advance. When the first audio signal S71 is lower than the predetermined signal level, that is, when the detection signal S75 is not supplied, the detection signal S7
Wait until 5 is supplied. When the first audio signal S71 is higher than the predetermined signal level, that is, when the detection signal S
If 75 is supplied, the process proceeds to Step F3.

In step F3, the control means 76 sets the first
The adjustment signal S76a for attenuating the variable audio signal S81 is generated. Based on the adjustment signal S76a, the first sound volume adjustment unit 81 gradually attenuates the first variable audio signal S81 and supplies the first variable audio signal S81 to the addition unit 83. That is, the signal level of the first variable audio signal S81 decreases.

In step F4, the delay time detecting means 73
Starts detection processing of the delay time Td when the detection signal S75 is supplied from the signal detection means 75. The delay time detecting means 73 includes first and second audio signals S71 and S72.
The delay time Td is detected from the correlation. When the delay time Td can be detected within the preset maximum delay time, the delay time detecting means 73 detects the detected delay time Td.
The delay time signal S73 indicating d is supplied to the control means 76.

In step F5, the control means 76 determines whether or not the delay time detecting means 73 has detected the delay time Td based on the supply of the delay time signal S73. When the delay time Td cannot be detected, that is, when the delay time signal S73 is not supplied, the process proceeds to step F8. If the delay time Td has been detected, that is, if the delay time signal S73 has been supplied, the process proceeds to step F6.

In step F6, the control means 76 supplies a signal indicating the delay time Td to the removing means 74, and proceeds to step F7. Upon receiving the signal indicating the delay time Td from the control unit 76, the removing unit 74 starts a removal process of removing a signal corresponding to the first audio signal S71 from the second audio signal S72.

In step F7, the control means 76
An adjustment signal S76b for increasing the variable audio signal S74 is generated, and the process returns to step F2. Based on the adjustment signal S76b, the second volume adjustment means 82 outputs the second variable audio signal S
82 is gradually increased from the zero level or a level near the zero level and supplied to the adding means 83. That is, the signal level of the second variable audio signal S82 increases.

At step F8, the control means 76
Is determined based on the presence or absence of the supply of the detection signal S75 from the signal detection means 75. If the first audio signal S71 is equal to or higher than the predetermined signal level, that is, if the detection signal S75 is supplied, the process returns to step F4, and the delay time detecting means 73 restarts the process of detecting the delay time Td. When the first audio signal S71 is lower than the predetermined signal level, that is, when the detection signal S75 is not supplied, the process proceeds to step F9.

At step F9, the control means 76
Then, an adjustment signal S76a for increasing the variable audio signal is generated, and the process returns to step F2. Note that the control means 76 controls the second
An adjustment signal S76b for setting the variable audio signal S82 to zero level or a level close thereto may be further generated. Based on the adjustment signal S76a, the first sound volume adjusting means 81
Supplies the first variable audio signal S81 to the adding means 83 while gradually increasing the first variable audio signal S81. That is, the first variable audio signal S
The signal level of 81 increases. As described above, when the delay time Td cannot be detected within the preset maximum delay time, when the first audio signal S71 is lower than the predetermined signal level, the first variable audio signal S81 is converted to the second variable audio signal S81. By setting the signal level of the audio signal S72, the second audio signal S72
72 can be supplied to the adding means 83 substantially.

If the delay time Td cannot be detected within the preset maximum delay time, the first audio signal S7
If 1 is less than the predetermined signal level, step F8
The process may return from step F8 to step F1 instead of proceeding from step F9 to step F9. In this way, the original state can be restored.

First and Second Variable Audio Signals Next, the signal levels of the first and second variable audio signals of the audio signal processing device 100 will be described with reference to FIGS. FIGS. 3 to 5 are explanatory diagrams exemplifying how the signal levels of the first and second variable audio signals change over time. 3 to 5, the horizontal axis indicates time t, and the vertical axis indicates the magnitude of the signal level.

The time T10 in FIGS. 3 to 5 indicates the time when the signal detection means 75 generates the detection signal S75. For example, it is assumed that the announcer at the site starts commentary immediately before time T10. Also, at time T20 in FIGS.
Is the time when the removing unit 74 starts the removing process.

The time TA in FIGS. 3 to 5D is
Based on the delay time signal S73 from the delay time detecting means 73, the time at which the control means 76 generates the adjustment signal S76b for increasing the second variable audio signal S82 is shown. This time TA is the time T at which the removal processing by the removal means 74 is started.
20, a predetermined time TX (= TA−T2)
0) has elapsed, and at time TA, the amount of attenuation of the signal corresponding to the first audio signal S71 in the removal signal S74 has reached a predetermined amount, and the first audio signal S71 in the removal signal S74 The time is such that the corresponding signal is sufficiently attenuated.

First and second audio signal processing apparatus 100
An example of the signal level of the variable audio signal will be described with reference to FIG. FIG. 3A shows an example of the signal level of the first variable audio signal S81. Before time T10,
The first variable sound signal S81 output from the first sound volume adjusting means 81 is the same as the second sound signal S72 input to the first sound volume adjusting means 81, and its signal level is L.
It is 10. At this time, the attenuation is the minimum value of zero.
From time T10 to time T11, the first variable audio signal S81 decreases to the signal level L11 (<L10).
From time T11 to time T20, the first variable audio signal S81 remains at the signal level L11. Time T20
From time T30, the signal level of the first variable audio signal S81 decreases to the zero level. After time T30, the signal level of the first variable audio signal S81 is at the zero level, and at this time, the amount of attenuation is at the maximum value and is in the cutoff state (cut state).

FIG. 3B shows a second variable audio signal S8.
One example of a signal level of 2 is shown. Before time T20, the signal level of the second variable audio signal S82 is at the zero level, the attenuation is at the maximum value, and the signal is in the cutoff state. From time T20 to time T30, the second variable audio signal S82 increases to the signal level L20 (fade-in). In this way, when the first variable audio signal S81 is at or near the zero level, the second variable audio signal S82 is set to the signal level L20. Time T3
After 0, the signal level of the second variable audio signal S82 remains at L20. At this time, the second volume control means 8
2 is the same as the removal signal S74 input to the second volume adjustment means 82, and the attenuation is the minimum value of zero.

FIG. 3C shows the second variable audio signal S8.
Another example of a signal level of 2 is shown. Before time T20, the signal level of the second variable audio signal S82 is at the zero level, the attenuation is at the maximum value, and the signal is in the cutoff state. From time T20 to time T40, the second variable audio signal S82 increases to the signal level L20 (fade-in). After time T40, the second variable audio signal S8
The signal level of No. 2 remains at L20. At this time, the second
The second variable audio signal S8 output by the
2 is a removal signal S input to the second volume adjusting means 82
74 and the attenuation is the minimum value of zero.

FIG. 3D shows the second variable audio signal S8.
Another example of a signal level of 2 is shown. Before the time TA, the signal level of the second variable audio signal S82 is at the zero level, the amount of attenuation is at the maximum value, and the state is in the cutoff state.
From time TA to time T40, the second variable audio signal S82 increases to the signal level L20 (fade-in). After time T40, the second variable audio signal S82
Remains at L20. At this time, the second variable audio signal S82 output by the second volume control unit 82
Is the removal signal S7 input to the second volume control means 82
4 and the amount of attenuation is the minimum value of zero.

First and second audio signal processing apparatus 100
Another example of the signal level of the variable audio signal will be described with reference to FIG. FIG. 4A shows the first variable audio signal S8.
1 is shown, and FIG. 4A shows FIG.
Therefore, the description is omitted.

FIG. 4B shows the second variable audio signal S8.
One example of a signal level of 2 is shown. Before time T30, the signal level of the second variable audio signal S82 is at the zero level, the attenuation is at the maximum value, and the cut state is established.
From time T30 to time T50, the second variable audio signal S82 increases to the signal level L20 (fade-in). As described above, when the first variable audio signal S81 becomes the zero level or a level near the zero level, the second variable audio signal S82 is increased. After time T50, the second
The signal level of the variable audio signal S82 remains at L20. At this time, the second volume output by the second
Is the same as the removal signal S74 input to the second sound volume adjusting means 82, and the attenuation is the minimum value of zero.

FIG. 4C shows the second variable audio signal S8.
Another example of a signal level of 2 is shown. Before time T30, the signal level of the second variable audio signal S82 is at the zero level, the attenuation is at the maximum value, and the state is in the cutoff state. From time T30 to time T60, the second variable audio signal S82 increases to the signal level L20 (fade-in). As described above, when the first variable audio signal S81 becomes the zero level or a level near the zero level, the second variable audio signal S82 is increased. After time T60, the signal level of the second variable audio signal S82 remains at L20. At this time, the second variable audio signal S82 output from the second volume adjustment unit 82 is the same as the removal signal S74 input to the second volume adjustment unit 82, and the attenuation is the minimum value of zero. .

FIG. 4D shows the second variable audio signal S8.
Another example of a signal level of 2 is shown. Before the time TA, the signal level of the second variable audio signal S82 is at the zero level, the amount of attenuation is at the maximum value, and the signal is in the cutoff state.
From time TA to time T60, the second variable audio signal S82 increases to the signal level L20 (fade-in). After time T60, the second variable audio signal S82
Remains at L20. At this time, the second variable audio signal S82 output by the second volume control unit 82
Is the removal signal S7 input to the second volume control means 82
4 and the amount of attenuation is the minimum value of zero.

First and second audio signal processing device 100
Another example of the signal level of the variable audio signal will be described with reference to FIG. FIG. 5A shows the first variable audio signal S8.
An example of one signal level is shown. Before time T10, the first variable sound signal S81 output from the first sound volume adjusting means 81 is the same as the second sound signal S72 input to the first sound volume adjusting means 81, and its signal level Is L10. At this time, the attenuation is the minimum value of zero. From time T10 to time T12, the signal level of the first variable audio signal S81 decreases to zero level. After the time T12, the signal level of the first variable audio signal S81 is at the zero level, and at this time, the attenuation is the maximum value, and the state is in the cutoff state.

FIG. 5B shows the second variable audio signal S8.
One example of a signal level of 2 is shown. Before time T20, the signal level of the second variable audio signal S82 is at the zero level, the attenuation is at the maximum value, and the signal is in the cutoff state. From time T20 to time T70, the second variable audio signal S82 increases to the signal level L20 (fade-in). After time T70, the second variable audio signal S82
Remains at L20. At this time, the second variable audio signal S82 output by the second volume control unit 82
Is the removal signal S7 input to the second volume control means 82
4 and the amount of attenuation is the minimum value of zero.

FIG. 5C shows the second variable audio signal S8.
Another example of a signal level of 2 is shown. Before time T20, the signal level of the second variable audio signal S82 is at the zero level, the attenuation is at the maximum value, and the signal is in the cutoff state. From time T20 to time T80, the second variable audio signal S82 increases to the signal level L20 (fade-in). After time T80, the second variable audio signal S8
The signal level of No. 2 remains at L20. At this time, the second
The second variable audio signal S8 output by the
2 is a removal signal S input to the second volume adjusting means 82
74 and the attenuation is the minimum value of zero.

FIG. 5D shows the second variable audio signal S8.
Another example of a signal level of 2 is shown. Before the time TA, the signal level of the second variable audio signal S82 is at the zero level, the attenuation is at the maximum value, and the signal is in the cut state. From time TA to time T80, the second variable audio signal S82 increases to the signal level L20 (fade-in). After time T80, the second variable audio signal S82
Remains at L20. At this time, the second variable audio signal S82 output by the second volume control unit 82
Is the removal signal S7 input to the second volume control means 82
4 and the amount of attenuation is the minimum value of zero.

As shown in FIGS. 3 to 5, the second variable audio signal S82 is increased after the start of the removal processing by the removal means 74 (after time T20), so that the second variable audio signal S82 is generated after the start of the removal processing. The removed signal S74 can be substantially supplied to the adding means 83. Also, the first audio signal S71
During the period from when the signal level becomes equal to or higher than the predetermined signal level until the start of the removal processing, the second variable audio signal S82 is attenuated so that the removal signal S74 generated before the start of the removal processing is reduced. It is possible to prevent the signal from being supplied to the adding means 83 and the output terminal 89. Also, by gradually changing the signal levels of the first and second variable audio signals S81 and S82, when the added signal (output signal) S85 is supplied to an earphone or the like and converted into sound, the signal level changes. It is possible to reduce discomfort.

3 to 5, the time interval from time T10 to time T11 is, for example, about 5 ms.
(Milliseconds). Also, from time T10 to time T
The time interval up to 20 may be, for example, about 1 s (second). Further, the time interval from time T20 to time T30 may be, for example, about 5 ms (millisecond).

The removing means 74 supplies a reaching signal indicating that the signal corresponding to the first audio signal S71 has reached a predetermined attenuation amount by the removing processing to the control means 76,
The control means 76 may generate an adjustment signal S76b for increasing the second variable audio signal S82 based on the arrival signal. The above embodiment is an exemplification of the present invention, and the present invention is not limited to the above embodiment.

[0063]

According to the audio signal processing apparatus of the present invention, the second audio signal and the removal signal obtained by removing the signal corresponding to the first audio signal from the second audio signal are converted into:
It is possible to add by changing the signal level. In addition, since the first and second sound volume adjusting means and the adding means are provided, the second audio signal and the removal signal can be added by changing the signal level, and the fade-in and fade-out can be performed in various ways. It can be done in a pattern.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an audio signal processing device according to the present invention.

FIG. 2 is a schematic flowchart illustrating an operation of the audio signal processing device of FIG. 1;

FIG. 3 is a first explanatory diagram illustrating signal levels of first and second variable audio signals.

FIG. 4 is a second explanatory diagram illustrating signal levels of first and second variable audio signals.

FIG. 5 is a third explanatory diagram illustrating signal levels of first and second variable audio signals.

FIG. 6 is a block diagram showing a configuration of a conventional audio signal processing device.

[Explanation of symbols]

10, 100 audio signal processing device, 11 first input terminal, 12 second input terminal, 21, 71 first analog / digital conversion means (A / D conversion means), 22, 7
2 ... second analog / digital conversion means (A / D conversion means), 23, 73 ... delay time detection means, 24, 74 ...
Removal means, 25, 85 ... digital / analog conversion means (D / A conversion means), 29, 89 ... output terminals, 75 ... signal detection means, 81 ... first volume adjustment means, 82 ... second volume adjustment means 83, adding means, S11, S61 first
Audio signals (analog audio signals), S12, S62 ... second audio signals (analog audio signals), S21, S71 ...
First audio signal (digital audio signal), S22, S7
2. Second audio signal (digital audio signal), S23,
S73: delay time signal, S24, S74: removal signal, S
75 detection signal, S76a, S76b adjustment signal, S8
1: first variable audio signal, S82: second variable audio signal, S83: addition signal.

Claims (16)

[Claims] A first audio signal and a second audio signal obtained by delaying the first audio signal are supplied, and when the first audio signal is higher than a predetermined signal level, Delay time detecting means for detecting a delay time of the second audio signal; and a signal corresponding to the first audio signal based on the delay time detected by the delay time detecting means. Removing means for generating a removal signal removed from the audio signal; first volume adjusting means for generating a first variable audio signal in which the signal level of the second audio signal is changed; and changing the signal level of the removal signal. An audio signal processing device comprising: a second volume adjusting unit configured to generate a second variable audio signal; and an adding unit configured to add the first and second variable audio signals. 2. The signal processing apparatus according to claim 1, wherein the first sound volume adjusting means attenuates the first variable audio signal from a signal level of the second audio signal when the first audio signal is higher than the predetermined signal level. And when the delay time detecting means cannot detect the delay time, the first variable audio signal is output after the first audio signal falls below the predetermined signal level. 2. The audio signal processing device according to claim 1, wherein the signal level is returned to the signal level of the second audio signal. 3. The first sound volume adjusting means attenuates the first variable audio signal from the signal level of the second audio signal when the first audio signal is higher than the predetermined signal level. To a signal level lower than that, and further attenuates to a zero level after the start of the removal processing by the removal means. The audio signal processing device according to claim 1, wherein the variable audio signal is increased from a zero level to a signal level of the removal signal. 4. The second sound volume adjusting means increases the second variable audio signal from zero level at the start of the removing process by the removing means, and sets the first variable audio signal to zero level or 4. The audio signal processing device according to claim 3, wherein the second variable audio signal is set to a signal level of the removal signal when the level becomes near the level. 5. The second sound volume adjusting means increases the second variable audio signal from a zero level when a preset predetermined time has elapsed since the removal processing was started by the removal means. The audio signal processing device according to claim 3. 6. The second sound volume adjustment means, wherein when the removal processing is started by the removal means and the amount of attenuation of a signal corresponding to the first audio signal in the removal signal reaches a predetermined amount, The audio signal processing device according to claim 3, wherein the second variable audio signal is increased from a zero level. 7. The first sound volume adjusting means attenuates the first variable audio signal from the signal level of the second audio signal when the first audio signal is higher than the predetermined signal level. To a signal level lower than that, and further attenuates to a zero level after the start of the removal processing by the removal means, wherein the second volume control means sets the first variable audio signal at or near the zero level. The audio signal processing device according to claim 1, wherein after the signal level reaches the level, the second variable audio signal is increased from zero level to a signal level of the removal signal. 8. The second sound volume adjusting means increases the second variable audio signal from the zero level when the first variable audio signal is at or near a zero level. Audio signal processing device. 9. The second variable audio signal, when a predetermined time has elapsed after the first variable audio signal has reached a zero level or a level close to the zero level, the second variable audio signal has a second level. The audio signal processing device according to claim 7, wherein the signal is increased from a zero level. 10. The second volume adjusting means, when the amount of attenuation of a signal corresponding to the first audio signal in the removal signal reaches a predetermined amount, sets the second variable audio signal to a zero level. The audio signal processing device according to claim 7, wherein: 11. The first sound volume adjusting means, when the first audio signal is equal to or higher than the predetermined signal level, the first sound volume adjusting means controls the first sound signal by the start of the removal processing by the removal means.
The variable audio signal is attenuated from the signal level of the second audio signal to a zero level or a level close to the zero level, and the second sound volume adjustment unit, after the start of the removal process by the removal unit, 3. The audio signal processing device according to claim 1, wherein the variable audio signal is increased from a zero level to a signal level of the removal signal. 12. The audio signal processing device according to claim 11, wherein said second volume adjusting means increases said second variable audio signal from zero level at the time of starting the removal processing by said removal means. 13. The second sound volume adjusting means increases the second variable audio signal from a zero level when a preset predetermined time has elapsed since the removal processing was started by the removal means. The audio signal processing device according to claim 11. 14. The second sound volume adjusting means, wherein when the removing processing is started by the removing means and the amount of attenuation of the signal corresponding to the first audio signal in the removed signal reaches a predetermined amount, The audio signal processing device according to claim 11, wherein the second variable audio signal is increased from a zero level. 15. A signal detecting means for generating a detection signal when the audio signal is equal to or higher than the predetermined signal level, wherein the predetermined signal level is a signal level within a range that the audio signal can take. And a signal level larger than noise is set in advance, and the delay time detection means starts the detection processing of the delay time based on the detection signal generated by the signal detection means. The audio signal processing device according to any one of the above. 16. The apparatus according to claim 1, wherein said removing means has an echo canceller for removing a signal corresponding to said first audio signal from said second audio signal by filtering.
6. The audio signal processing device according to any one of 5.