JP2008141524A - Acoustic processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acoustic processor by which user recognizes a state of a virtual speaker being oriented and achieves a virtual surround function. <P>SOLUTION: The acoustic processor is characterized by providing a virtual surround processing means (110) for performing virtual surround processing to an input audio signal to output a processed audio signal and a switching means (107) in which the audio signal and the processed audio signal output from the virtual surround processing means are input and switching output to the audio signal and the processed audio signal by every predetermined time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an acoustic processing apparatus, and more particularly to an acoustic processing apparatus that performs virtual surround signal processing.

  There is known a so-called virtual surround device, for example, a sound field reproduction device that allows sound to be continuously heard from the side or the back without actually placing the speaker on the side or the back of the listener (for example, Patent Document 1). In such a virtual surround device, sound can be continuously heard from a virtual speaker that is localized to the side or rear of the listener by simply placing the speaker in front of the listener. Realistic sound reproduction can be performed in real time.

  In such a virtual surround device, when the virtual surround function is switched from OFF to ON, it can be recognized that the virtual speaker is localized most by the user, and the original effect can be realized. However, if the virtual surround function is always turned on, it seems that the virtual speaker is localized and the original effect cannot be exhibited in some cases.

JP-A-7-288900 (FIG. 2)

  Accordingly, an object of the present invention is to provide an acoustic processing device that can solve the above-described problems.

  It is another object of the present invention to provide an acoustic processing apparatus that allows a user to recognize how a virtual speaker is localized and to feel a virtual surround function.

The audio processing apparatus according to the present invention includes a virtual surround processing unit that performs a virtual surround process on an input audio signal and outputs a processed audio signal, and an audio signal and a processed audio signal output from the virtual surround processing unit. There is provided switching means for switching between an input audio signal and a processed audio signal every predetermined time.
Moreover, it is preferable that the acoustic processing apparatus according to the present invention further includes a source that outputs an audio signal, or further includes an output unit that outputs a signal from the switching unit.

The acoustic processing device according to the present invention includes virtual surround processing means for outputting a processed audio signal that is input with an audio signal and subjected to virtual surround processing on the audio signal, and the virtual surround processing means performs virtual surround processing at predetermined time intervals. The processing level is controlled.
Moreover, it is preferable that the acoustic processing apparatus according to the present invention further includes a source that outputs an audio signal, or further includes an output unit that outputs a signal from the virtual surround processing means.

  According to the sound processing apparatus of the present invention, since the virtual surround processing function is turned on after the virtual surround processing function is turned off, the comparison is made as a comparison between the OFF state and the ON state. It is possible to feel the virtual surround processing function and to give the user the maximum effect of turning on the virtual surround processing function.

  Hereinafter, a sound processing apparatus according to the present invention will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to these embodiments, but extends to the invention described in the claims and equivalents thereof.

  FIG. 1 is a diagram illustrating an arrangement example of speakers in a vehicle 1 including a sound processing device according to the present invention.

  The vehicle 1 includes a passenger seat 12, a driver seat 13, and a rear seat 17, and includes a passenger seat headrest 21, a driver seat headrest 22, a rear seat left headrest 23, a rear seat right headrest 24, and the like. The front passenger seat 12 is equipped with a front speaker first speaker 40 and a second speaker 41. The driver's seat 13 is equipped with a front speaker third speaker 42 and a fourth speaker 43. Further, the rear seat left headrest 23 is equipped with a rear seat first speaker 50 and a second speaker 51, and the rear seat right headrest 24 is equipped with a rear seat third speaker 52 and a fourth speaker 53. Yes. The front seat first speaker 40 to the fourth speaker 43 and the rear seat first speaker 50 to the fourth speaker 53 are driven by the acoustic signal processing device 100.

  FIG. 2 is a diagram showing an arrangement example of speakers in the rear seat.

  Two speakers 50 and 51 are mounted on both sides of the rear seat left headrest 23 of the rear seat 17, and two speakers 52 and 53 are mounted on both sides of the rear seat right headless road 24. The number of speakers for the rear seats is not limited to two for each headrest, but may be one or more. In this example, two headrests are arranged in the rear seat, but the present invention is not limited to this, and three headrests may be provided.

  FIG. 4 is a diagram illustrating the headrest.

  The headrest shown in FIG. 4 can be used not only for the rear seat 17 but also for the passenger seat 12 and the driver seat 13. Note that the front seat first speaker 40 to the fourth speaker 43 and the rear seat first speaker 50 to the fourth speaker 53 are general cone type speakers that are not strong in directivity.

  FIG. 4 is a diagram showing a schematic configuration of the sound processing system.

  The acoustic processing system includes an acoustic signal processing device 100, various speakers (first front speaker 40 to fourth speaker 43, first rear seat speaker 50 to fourth speaker 53), and the like.

  The acoustic signal processing apparatus 100 includes a control unit 101 including a CPU, a ROM and a RAM, a memory 102 including a recording medium, an operation unit 103 including various buttons, a DVD player 104, a CD / MD playback unit 105, A radio receiver 106, a switching circuit 107, a virtual surround processing circuit 110, a distribution circuit 120, a signal amplifier 130, and the like are included. Note that the DVD player 104, the CD / MD playback unit 105, and the radio reception unit 106 that function as a source for outputting an audio signal may be separate from the acoustic signal processing device 100, and the acoustic processing system You may have other sources, such as TV receiving part, HD (hard disk) reproducing part, and a navigation part. In FIG. 4, the acoustic signal processing device 100 is configured to have various sources, but the various sources may be separated from the acoustic signal processing device 100. Further, the acoustic signal processing apparatus 100 itself may be configured to include various speakers.

  The audio signal output from the source (for example, the DVD playback unit 104) selected by the control unit 101 is input to the switching circuit 107 and the virtual surround processing circuit 110.

  When the control unit 101 turns off the virtual surround function processing, the switching circuit 107 is controlled so that the audio signal output from the selected source is output to the distribution circuit 120 as it is. The audio signal input to the distribution circuit 120 is distributed so as to be output from a predetermined speaker, amplified by the signal amplifier 130, and output to each speaker. The signal amplifying unit 130 includes an amplifier corresponding to each speaker unit of the first speaker 40 to the fourth speaker 43 for the front seat and an amplifier corresponding to the first speaker 50 to the fourth speaker 53 for the rear seat. Yes.

  On the other hand, when the control unit 101 turns on the virtual surround function process, the switching circuit 107 is controlled so that the audio signal that has been subjected to the virtual surround process in the virtual surround process circuit 110 is output to the distribution circuit 120. The processed audio signal input to the distribution circuit 120 is distributed so as to be output from a predetermined speaker by the distribution circuit 120, amplified by the signal amplification unit 130, and output to each speaker. The virtual surround processing circuit 110 is configured to always output an audio signal that has been subjected to virtual surround processing.

  That is, when the control unit 101 turns on the virtual surround function process, for example, for the passenger 10 sitting in the passenger seat 12, in addition to the first speaker 40 and the second speaker 41 that are actually arranged, 44 and FIG. It is perceived as if the output sound is localized at the position indicated by 45 (as if there is a virtual speaker). By such a virtual surround function, the passenger 10 sitting in the passenger seat 12 can perceive the output sound from four directions only with two speakers, and thus it is possible to receive a powerful and realistic sound in real time. .

  FIG. 5 is a diagram illustrating the switching timing.

  FIG. 5A shows the first control timing of the switching circuit 107. In FIG. 5A, time t1 indicates the time when the output of the audio signal from the source is started (for example, the time when the sound processing system is turned on and the DVD is started to be played back). From time t1 to t2, the control unit 101 controls the switching circuit 107 so that the audio signal from the source (for example, the DVD playback unit 104) is output to the distribution circuit 120 as it is.

  At time t2, the control unit 101 controls the switching circuit 107 to perform switching control so that only the processed audio signal from the virtual surround processing circuit 110 is output to the distribution circuit 120. Note that the control unit 101 and the switching circuit 107 may be configured integrally.

  That is, in the case of the timing control shown in FIG. 5A, the user initially receives normal audio output (audio output not subjected to virtual surround function processing) at the beginning of listening to the audio, but at the time t2. Since the audio output that has been subjected to the virtual surround function processing is started to be heard, it can be felt that the virtual surround function is functioning well.

  The time from time t1 to t2 in FIG. 5A is predetermined (for example, 2 seconds), and is stored in the memory 102 or the like as control data.

  FIG. 5B is a diagram illustrating the second control timing of the switching circuit 107. In FIG. 5B, time t1 indicates the time when the output of the audio signal from the source is started (for example, when the sound processing system is turned on and the DVD is started to be played back). From time t1 to t2, the control unit 101 controls the switching circuit 107 so that the audio signal from the source (for example, the DVD playback unit 104) is output to the distribution circuit 120 as it is.

  Next, from time t2 to time t3, the control unit 101 controls the switching circuit 107 so as to output the processed audio signal from the virtual surround processing circuit 110 to the distribution circuit 120 while gradually increasing it, At the same time, control is performed so that the audio signal from the source that has been output until time t2 is output to the distribution circuit 120 while being gradually reduced (cross-fade processing). Note that the gradual switching process is not limited to the crossfade process, and other processing methods such as, for example, continuous update of the filter coefficient of the virtual surround process may be used.

  Therefore, at time t 3, the control unit 101 controls the switching circuit 107 so that only the processed audio signal from the virtual surround processing circuit 110 is completely output to the distribution circuit 120. Further, the processed audio signal from the virtual surround processing circuit 110 is controlled to be output to the distribution circuit 120 while being gradually reduced, and at the same time, the audio signal from the source is output to the distribution circuit 120 while being gradually increased. You may make it control.

  That is, in the case of the timing control shown in FIG. 5B, when the user starts listening to the sound, the user receives normal sound output (sound output not subjected to the virtual surround function processing), but then gradually ( Since it starts listening to the sound output that has been processed by the virtual surround function (not suddenly), the user can feel that the virtual surround function is working well.

  The time from the time t1 to t2 and the time from the time t2 to t3 in FIG. 5B are predetermined (for example, 2 seconds and 1 second), and are stored in the memory 102 or the like as control data.

  5 (a) and 5 (b), the time t1 is the time when the output of the audio signal from the source is started. For example, when the source is switched (for example, switching from the DVD playback unit 104 to the radio reception unit 106). Time). That is, when switching the source, as shown in FIG. 5 (a) or (b), the normal audio output is first performed and the processed audio output of the virtual surround function processing is output after a predetermined time. May be.

  Also, when the DVD playback unit 104, CD / MD playback unit 105, or radio reception unit 106 is used as a source, when changing a DVD chapter, when changing a CD / MD track, or when changing radio tuning, As shown in 5 (a) or (b), control may be performed so that normal audio output is initially performed and the processed audio output of the virtual surround function processing is output after a predetermined time.

  Furthermore, although the above-described acoustic processing system has been described using an in-vehicle speaker, the acoustic processing system according to the present invention can be used for, for example, a floor-type speaker or an earphone other than the in-vehicle speaker. is there.

  FIG. 6 is a diagram for explaining the principle of virtual surround.

  The virtual surround processing circuit 110 includes an original sound field (region where the virtual speakers 4 and 5 are perceived) characteristic addition unit 111, a crosstalk cancellation processing unit 112, and the like.

  In the original sound field characteristic adding unit 111, the path SL from the virtual speaker 4 to the user's left ear, the path SR from the virtual speaker 4 to the user's right ear, the path SL 'from the virtual speaker 5 to the user's left ear, the virtual speaker A characteristic corresponding to the route SR ′ from 5 to the user's right ear is added to the L channel signal and the R channel signal input to the virtual surround processing circuit 110.

  In the crosstalk cancellation processing unit 112, a path LL from the actual speaker 2 to the user's left ear, a path LR from the actual speaker 2 to the user's right ear, a path RL from the actual speaker 3 to the user's left ear, A characteristic corresponding to the route RR from the actual speaker 3 to the user's right ear is further added and output as an audio signal TL to the actual speaker 2 and an audio signal TR to the actual speaker 3.

Here, for the L channel signal, TL = (SL * RR-SR * RL) / D, TR = (SR * LL-SL * LR) / D, and D = LL * RR-LR * RL. . For the R channel signal, SL is replaced with SL ′ and SR is replaced with SR ′ in the above formula.
By performing such signal processing, the virtual speakers 4 and 5 can be perceived as if they exist at the positions shown in FIG.

  The virtual surround processing circuit 110 shown in FIG. 4 is configured in consideration of the actual speaker and the position where the virtual speaker is to be localized based on the principle shown in FIG. The circuit 110 itself may be operated based on other principles.

  FIG. 7 is a diagram showing another arrangement example of the speakers.

  In FIG. 7, instead of the first front speaker 40 and the second speaker 41 described above, a first array speaker 70 and a second array speaker 71 are arranged at the shoulder portions of the backrest of the passenger seat 12, respectively. . Thus, in the present invention, an array speaker can be used in place of the first front seat speaker 40 and the second speaker 41 described above.

  Further, as shown in the figure, the four speaker units 75 to 78 included in the second array speaker 71 are arranged in an arc shape so that the distances between the passenger seat 12 and the right ear of the passenger 10 are all equal. . Although not shown, the distance between each speaker unit of the first array speaker 70 and the left ear 60 of the passenger 10 in the passenger seat 12 is set to be equal. With such an arrangement, the sound output from the first array speaker 70 is localized near the left ear of the passenger 10 in the passenger seat, and the sound output from the second array speaker 71 is the passenger in the passenger seat. It will be located in the vicinity of the 10 right ear. Note that the number of speaker units of the array speaker is not limited to four, and it is not always necessary to arrange them in an arc shape so that the distances between the passenger seat 12 and the right ear of the passenger 10 are all equal. . Further, although the passenger seat 12 has been described with reference to FIG. 7, the driver seat 13 can be similarly changed.

  FIG. 8 is a diagram illustrating a schematic configuration of another acoustic processing system.

  The acoustic processing system shown in FIG. 8 is different from the acoustic processing system shown in FIG. 4 in that the acoustic signal processing apparatus 200 of the acoustic processing system shown in FIG. 8 does not have the switching circuit 107 and controls the virtual surround processing circuit 210 itself. This is only a point where the unit 101 performs ON / OFF control. In FIG. 8, the same components as those in FIG.

  Based on the control from the control unit 101, the virtual surround processing circuit 210 outputs the processed audio signal to the distribution circuit by turning on the virtual surround function processing, and turns off the virtual surround function processing from the source. Are directly output to the distribution circuit. Therefore, the acoustic processing system shown in FIG. 8 can perform the switching process as shown in FIG. 5, similarly to the acoustic processing system shown in FIG. 4, even without the switching circuit 107.

  FIG. 9 is a diagram showing another example of the switching timing, and pays attention only to the increase / decrease of the processing level of the virtual surround processing circuit 210.

  As shown in FIG. 9, before the time t1 and after the time t4, the virtual surround processing circuit 210 is in a state in which the virtual surround function processing is turned off, and outputs the audio signal from the source to the distribution circuit as it is. From time t1 to time t2, the virtual surround processing circuit 210 gradually increases the processing level, and from time t2 to time t3, the virtual surround processing circuit 210 holds the processing level constant, and from time t3. At time t4, the virtual surround processing circuit 210 gradually reduces the processing level. That is, from time t1 to time t4, the virtual surround processing circuit 210 is in a state in which the virtual surround function processing is ON, and the processed audio signal is output to the distribution circuit 120. Note that the processing level switching timing in FIG. 9 is an example. For example, as shown in FIG. 5A, control may be performed so that the processing level is switched ON / OFF at a certain time.

  The time from time t1 to time t2 and the time from time t3 to time t4 in FIG. 9 are determined in advance (for example, 1 second) and are stored in the memory 102 or the like as control data.

FIG. 1 is a diagram showing an arrangement example of speakers in a vehicle 1 including a sound processing system according to the present invention. It is the figure which showed the example of arrangement | positioning of a speaker. It is a figure which shows a headrest. It is a figure showing the outline composition of the sound processing system concerning the present invention. It is a figure which shows a switching timing. It is a figure for demonstrating the principle of virtual surround. It is the figure which showed the other example of arrangement | positioning of a speaker. It is a figure which shows schematic structure of the other acoustic processing system which concerns on this invention. It is a figure which shows another switching timing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Driver's seat 13 Passenger seat 17 Rear seat 21-24 Headrest 40-43 Speaker 50-53 Speaker 100, 200 Acoustic signal processing apparatus 101 Control part 103 Operation part 107 Switching circuit 110, 210 Virtual surround processing circuit

Claims (8)

Virtual surround processing means for performing virtual surround processing on the input audio signal and outputting a processed audio signal;
Switching means for inputting the audio signal and the processed audio signal output from the virtual surround processing means and switching the output between the audio signal and the processed audio signal every predetermined time;
A sound processing apparatus comprising:   The switching means gradually reduces the sound signal and gradually increases the processed sound signal, or gradually decreases the processed sound signal and gradually increases the sound signal. The sound processing apparatus according to claim 1, wherein the sound processing apparatus switches to a processed audio signal. A source that outputs audio signals;
Virtual surround processing means for performing virtual surround processing on the audio signal and outputting a processed audio signal;
Switching means for inputting the audio signal and the processed audio signal output from the virtual surround processing means and switching the output between the audio signal and the processed audio signal every predetermined time;
A sound processing apparatus comprising: A source that outputs audio signals;
Virtual surround processing means for performing virtual surround processing on the audio signal and outputting a processed audio signal;
Switching means for inputting the audio signal and the processed audio signal output from the virtual surround processing means and switching the output between the audio signal and the processed audio signal every predetermined time;
An output unit for outputting a signal from the switching means;
A sound processing apparatus comprising: A virtual surround processing means for outputting a processed audio signal obtained by inputting an audio signal and performing a virtual surround process on the audio signal;
The virtual surround processing means controls the processing level of virtual surround processing every predetermined time.   The sound processing apparatus according to claim 5, wherein the virtual surround processing unit gradually increases or decreases the processing level. A source that outputs audio signals;
Virtual surround processing means for inputting the audio signal and outputting a processed audio signal obtained by performing virtual surround processing on the audio signal;
The virtual surround processing means controls the processing level of virtual surround processing every predetermined time. A source that outputs audio signals;
Virtual surround processing means for outputting a processed audio signal obtained by performing virtual surround processing on the audio signal when the audio signal is input, and the virtual surround processing means controls a processing level of the virtual surround processing every predetermined time,
An output unit for outputting a signal from the virtual surround processing means;
A sound processing apparatus comprising:

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