JP2020162001A - Acoustic system and mobile body - Google Patents

Abstract

To provide an acoustic system that enables a user to obtain a sufficient surrounded feeling with a more natural sound field feeling even when the user sits in any of a front seat and a rear seat.SOLUTION: An acoustic system 2 comprises: a left front speaker 10FL and a right front speaker 10FR; a left front headrest speaker 10HFL and a right front headrest speaker 10HFR; a left rear headrest speaker 10HRL and a right rear headrest speaker 10HRR; and a control section 14. The control section 14 outputs an acoustic signal on which first processing has been performed to the left front headrest speaker 10HFL and the right front headrest speaker 10HFR. The control section 14 outputs an acoustic signal on which second processing has been performed to the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to an acoustic system and a moving body equipped with the acoustic system.

An acoustic system for reproducing an audio source is installed in the passenger compartment of a vehicle such as an automobile. The acoustic system includes a front speaker arranged in front of the front seat in the vehicle interior and a rear speaker arranged in the vicinity of the rear seat in the vehicle interior (see, for example, Patent Document 1).

When the audio source is reproduced in the vehicle interior, the front channel signal and the rear channel signal are output to the front speaker and the rear speaker, respectively. As a result, music or the like based on the audio source is output from each of the front speakers and the rear speakers, and a surround sound field is generated in the vehicle interior.

Japanese Unexamined Patent Publication No. 2019-18729 Japanese Patent No. 6188923

In the conventional acoustic system described above, the distance between the front seat and the rear speaker is longer than the distance between the front seat and the front speaker. Therefore, in order for the user seated on the front seat to obtain a sufficient surround feeling, it is necessary to make the volume output from the rear speaker higher than the volume output from the front speaker. However, in this case, for another user seated on the rear seat, the volume output from the rear speaker becomes too loud, and there arises a problem that the balance of the surround feeling is lost.

On the other hand, in order for another user seated on the rear seat to obtain a sufficient surround feeling, it is necessary to suppress the volume output from the rear speaker to be lower than in the above case. However, in this case, for the user seated on the front seat, the volume output from the rear speaker becomes too low, which causes a problem that the balance of the surround feeling is lost.

Therefore, there is known a technique of utilizing a speaker attached to the headrest of each seat so that the balance of the surround feeling is not disturbed regardless of whether the user is seated on the front seat or the rear seat (for example). , See Patent Document 2 above). The speaker attached to the headrest can adjust the volume balance, frequency characteristics, delay amount, etc. with the front speaker for each seat.

However, since the headrest is placed close to the position of the seated user's head, in order to realize a more spacious surround feeling, the surround speaker is virtually placed at an appropriate position behind the user. It is necessary to perform sound image localization processing such as arranging in.

In the above-mentioned sound image localization processing in Patent Document 2, in order to realize a more expansive surround sound field, sound image localization processing in which a plurality of virtual sound sources distributed in the height direction and the front-back and left-right directions are set is performed. .. By generating a plurality of virtual sound sources, the effect of expanding the sound field in the space where the sound sources are arranged can be expected.

However, when multiple adjacent virtual sound sources are individually subjected to sound image localization processing with a binaural filter based on their respective positions, and the outputs are mixed and reproduced from one speaker, the output signals of the plurality of adjacent virtual sound sources are displayed. Phase interference occurs between them. As a result, there arises a problem that the timbre and the feeling of the sound field become unnatural.

Therefore, the present disclosure provides an acoustic system capable of obtaining a sufficient surround feeling with a more natural sound field feeling regardless of whether the user is seated on the front seat or the rear seat, and a moving body provided with the same. To do.

The acoustic system according to one aspect of the present disclosure is for reproducing an audio source in a room in which a front seat having a first headrest and a rear seat having a second headrest for sitting are arranged side by side in the front-rear direction. In the room, a front speaker arranged in front of the front seat, a first headrest speaker arranged in the first headrest, and a second headrest arranged in the second headrest. 2 headrest speakers, and a control unit that generates an acoustic signal based on the audio source and outputs the generated acoustic signal to the front speaker, the first headrest speaker, and the second headrest speaker. The control unit applies the first process in consideration of the positional relationship between the front speaker and the front seat to the acoustic signal, and the acoustic signal subjected to the first process is the first. The acoustic signal is output to the headrest speaker, and the acoustic signal is subjected to a second process in consideration of the positional relationship between the front speaker and the rear seat, and the acoustic signal subjected to the second process is applied to the second headrest. Output to the speaker.

It should be noted that these comprehensive or specific embodiments may be realized in a recording medium such as a system, method, integrated circuit, computer program or computer-readable CD-ROM, and the system, method, integrated circuit, computer program. And any combination of recording media may be realized.

In the acoustic system and the like of the present disclosure, a sufficient surround feeling can be obtained with a more natural sound field feeling regardless of whether the user is seated on the front seat or the rear seat.

It is a top view which shows the vehicle which mounted the acoustic system which concerns on embodiment. It is a block diagram which shows the structure of the acoustic system which concerns on embodiment. It is a figure which shows the left front door of the vehicle which mounted the acoustic system which concerns on embodiment. It is a figure which shows the headrest of the front seat of the vehicle which mounted the acoustic system which concerns on embodiment. It is a figure which shows the headrest of the rear seat of the vehicle which mounted the acoustic system which concerns on embodiment. It is a side view which shows the vehicle interior of the vehicle which mounted the acoustic system which concerns on embodiment. It is a figure for demonstrating the distribution destination of each channel signal in the acoustic system which concerns on embodiment. It is a flowchart which shows the operation flow of the acoustic system which concerns on embodiment.

In order to solve the above-mentioned problems, in the sound system according to one aspect of the present disclosure, a front seat having a first headrest and a rear seat having a second headrest for the user to sit are arranged side by side in the front-rear direction. An acoustic system for reproducing an audio source in a room, the front speaker arranged in front of the front seat in the room, the first headrest speaker arranged in the first headrest, and the said. A second headrest speaker arranged on the second headrest and an acoustic signal are generated based on the audio source, and the generated acoustic signal is used as the front speaker, the first headrest speaker, and the second. The control unit includes a control unit that outputs to the headrest speaker, and the control unit performs a first process on the acoustic signal in consideration of the positional relationship between the front speaker and the front seat, and the first process is performed. The sound signal was output to the first headrest speaker, and a second process considering the positional relationship between the front speaker and the rear seat was applied to the acoustic signal, and the second process was performed. The acoustic signal is output to the second headrest speaker.

According to this aspect, the first headrest speaker is arranged on the first headrest of the front seat, and the second headrest speaker is arranged on the second headrest of the rear seat. The acoustic signal output to the first headrest speaker is subjected to the first processing in consideration of the positional relationship between the front speaker and the front seat, so that a sufficient surround feeling can be obtained in the front seat. It is adjusted so that. Further, the acoustic signal output to the second headrest speaker is subjected to the second processing in consideration of the positional relationship between the front speaker and the rear seat, so that a sufficient surround feeling can be obtained in the rear seat. It is adjusted so that. Therefore, regardless of whether the user is seated on the front seat or the rear seat, a sufficient surround feeling can be obtained with a more natural sound field feeling.

For example, the first process is a process for delaying the timing of sound output from the first headrest speaker by the first delay time from the timing of sound output from the front speaker. In the second process, the timing at which the sound is output from the second headrest speaker is longer than the timing at which the sound is output from the front speaker, and the second delay time is longer than the first delay time. It may be configured to be a process for delaying by a time.

According to this aspect, the user can experience a substantially even surround sound field regardless of whether the user is seated on the front seat or the rear seat.

For example, as the first process, the control unit has a first sound image for localizing a sound image of a sound output from the first headrest speaker to a first position behind the first headrest. The localization process is applied to the first channel signal included in the acoustic signal, the first channel signal subjected to the first sound image localization process is output to the first headrest speaker, and the second As the process of, the second sound image localization process for localizing the sound image of the sound output from the second headrest speaker to a second position different from the first position behind the second headrest. Is applied to the second channel signal included in the acoustic signal, and the second channel signal subjected to the second sound image localization process is output to the second headrest speaker. Good.

According to this aspect, by localizing the sound image of the sound output from the first headrest speaker to the first position behind the first headrest, the user seated on the front seat can obtain an effective surround sound. You can experience the place. Further, by localizing the sound image of the sound output from the second headrest speaker to the second position behind the second headrest, the user seated on the rear seat can experience an effective surround sound field. Can be done.

For example, as the first process, the control unit has a third sound image for localizing the sound image of the sound output from the first headrest speaker to a third position above the first headrest. The localization process is applied to the third channel signal included in the acoustic signal, and the first channel signal subjected to the first sound image localization process and the third channel signal subjected to the third sound image localization process. Channel signal is output to the first headrest speaker, and as the second process, the sound image of the sound output from the second headrest speaker is output to the third position above the second headrest. A fourth sound image localization process for localizing to a fourth position different from the above is applied to the fourth channel signal included in the acoustic signal, and the second sound image localization process is performed on the second channel. The signal and the fourth channel signal subjected to the fourth sound image localization process may be configured to be output to the second headrest speaker.

According to this aspect, the user seated on the front seat is more effective by localizing the sound image of the sound output from the first headrest speaker to the third position above the first headrest. You can experience the surround sound field. Further, by localizing the sound image of the sound output from the second headrest speaker to the fourth position above the second headrest, the user seated on the rear seat can experience a more effective surround sound field. can do.

For example, the acoustic signal may be configured to be a three-dimensional acoustic signal for generating a three-dimensional sound field in the room.

According to this aspect, a three-dimensional sound field can be generated in the room.

For example, the three-dimensional acoustic signal is a signal that divides the frequency band of a predetermined channel signal of the acoustic signal into a channel that localizes the high frequency side upward and a channel that localizes the low frequency side downward. It may be configured as there is.

According to this aspect, it is possible to generate a three-dimensional sound field that gives a more natural sound field feeling.

For example, the room may be configured to be a room of a moving body that moves with the user on board.

According to this aspect, a sufficient surround feeling can be obtained with a more natural sound field feeling regardless of whether the user on the moving body is seated on the front seat or the rear seat.

The moving body according to one aspect of the present disclosure is a moving body that moves with a user on board, and includes any of the above-mentioned acoustic systems mounted in the room of the moving body.

According to this aspect, a sufficient surround feeling can be obtained with a more natural sound field feeling regardless of whether the user on the moving body is seated on the front seat or the rear seat.

It should be noted that these comprehensive or specific embodiments may be realized in a recording medium such as a system, method, integrated circuit, computer program or computer-readable CD-ROM, and the system, method, integrated circuit, computer program. Alternatively, it may be realized by any combination of recording media.

Hereinafter, embodiments will be specifically described with reference to the drawings.

It should be noted that all of the embodiments described below show comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, steps, the order of steps, etc. shown in the following embodiments are examples, and are not intended to limit the present disclosure. Further, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept are described as arbitrary components.

(Embodiment)
[1. Acoustic system configuration]
First, the configuration of the acoustic system 2 according to the embodiment will be described with reference to FIGS. 1 to 7. FIG. 1 is a top view showing a vehicle 4 equipped with the acoustic system 2 according to the embodiment. FIG. 2 is a block diagram showing a configuration of an acoustic system 2 according to an embodiment. FIG. 3 is a diagram showing a left front door 16 of a vehicle 4 on which the acoustic system 2 according to the embodiment is mounted. FIG. 4 is a diagram showing a headrest 22 of the front seat 20 of the vehicle 4 on which the acoustic system 2 according to the embodiment is mounted. FIG. 5 is a diagram showing a headrest 26 of the rear seat 24 of the vehicle 4 on which the acoustic system 2 according to the embodiment is mounted. FIG. 6 is a side view showing the interior of the vehicle 4 on which the acoustic system 2 according to the embodiment is mounted. FIG. 7 is a diagram for explaining a distribution destination of each channel (CH) signal in the acoustic system 2 according to the embodiment.

As shown in FIG. 1, the acoustic system 2 according to the embodiment is mounted in a vehicle interior (an example of an interior) of a vehicle 4 such as an automobile, and is used to generate a three-dimensional sound field in the vehicle interior of the vehicle 4. It is a sound system. The three-dimensional sound field is a surround sound field having a three-dimensional sound spread, in other words, a surround sound field having a sound spread in the pitch direction in addition to the two-dimensional sound spread. The vehicle 4 is an example of a moving body that moves with a user such as a driver 6 and a passenger 8 (see FIG. 6) on board.

As shown in FIG. 2, the acoustic system 2 includes a speaker group 10, an audio reproduction unit 12, and a control unit 14.

The speaker group 10 outputs a sound based on a three-dimensional acoustic signal output from an amplifier unit 34 (described later) of the control unit 14. As shown in FIG. 1, the speaker group 10 includes a plurality of speakers arranged in the vehicle interior of the vehicle 4, that is, a left front speaker 10FL (an example of a front speaker) and a right front speaker 10FR (an example of a front speaker). , Left front headrest speaker 10HFL (an example of a first headrest speaker), right front headrest speaker 10HFR (an example of a first headrest speaker), and left rear headrest speaker 10HRL (an example of a second headrest speaker). And a right rear headrest speaker 10HRR (an example of a second headrest speaker).

As shown in FIGS. 1 and 3, the left front speaker 10FL is arranged on the vehicle interior side of the left front door 16 of the vehicle 4. Further, as shown in FIG. 1, the right front speaker 10FR is arranged on the vehicle interior side of the right front door 18 of the vehicle 4. That is, the left front speaker 10FL and the right front speaker 10FR are arranged in front of the front seat 20 in the vehicle interior of the vehicle 4.

As shown in FIG. 6, the front seat 20 is a driver's seat for the driver 6 to sit on, and a passenger's seat for a passenger (not shown) other than the driver 6 to sit on. In the present specification, the term "forward" means the forward direction of the vehicle 4 (leftward in FIG. 6).

As shown in FIGS. 1 and 4, the left front headrest speaker 10HFL and the right front headrest speaker 10HFR are arranged inside the headrest 22 (an example of the first headrest) of the front seat 20 in the vehicle interior of the vehicle 4. .. The sound emitting surfaces of the left front headrest speaker 10HFL and the right front headrest speaker 10HFR are exposed on the front surface of the headrest 22.

As shown in FIGS. 1 and 5, the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR are arranged inside the headrest 26 (an example of the second headrest) of the rear seat 24 in the vehicle interior of the vehicle 4. The sound emitting surfaces of the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR are exposed on the front surface of the headrest 26.

As shown in FIG. 6, the rear seat 24 is a rear seat for a passenger 8 other than the driver 6 to be seated, and is arranged behind the front seat 20. That is, the front seat 20 and the rear seat 24 are arranged side by side in the front and rear of the vehicle interior of the vehicle 4. In the present specification, the term "rear" means the backward direction of the vehicle 4 (to the right in FIG. 6).

The audio reproduction unit 12 is mounted on, for example, an audio device having an audio function. The audio playback unit 12 reproduces an audio source such as a CD (Compact Disc), a DVD (Digital Versailles Disc), a BD (Blu-ray (registered trademark) Disc), a hard disk, or a semiconductor memory, for example, and has three or more channels. The multi-channel acoustic signal of is output to the control unit 14. Here, the multi-channel acoustic signal is, for example, a digital acoustic signal indicating music or the like.

The control unit 14 includes a DSP (Digital Signal Processor) 28, a converter unit 32, and an amplifier unit 34.

The multi-channel audio signal of the audio source reproduced by the audio reproduction unit 12 is input to the DSP 28. The DSP 28 generates a three-dimensional acoustic signal (an example of an acoustic signal) for generating a three-dimensional sound field in the vehicle interior of the vehicle 4 based on the input multi-channel acoustic signal. Further, the DSP 28 performs digital signal processing for adjusting, for example, volume, phase, frequency characteristics, etc., on a plurality of channel signals included in the generated three-dimensional acoustic signal, and a plurality of digital signal processes. It is determined how the channel signal is distributed to the speaker group 10.

Here, the three-dimensional acoustic signal is, for example, a left front channel signal, a right front channel signal, and a left front surround channel signal (a left front surround channel signal) which is a rear channel signal reproduced by a user seated on the front seat 20 as a plurality of channel signals. An example of a first channel signal), a right front surround channel signal (an example of a first channel signal), a left front height channel signal (an example of a third channel signal), and a right front height channel signal (an example of a third channel signal). An example of a channel signal), a left rear surround channel signal (an example of a second channel signal) and a right rear surround channel signal (an example of a second channel signal) which are rear channel signals reproduced by a user seated on the rear seat 24. And, a left rear height channel signal (an example of a fourth channel signal) and a right rear height channel signal (an example of a fourth channel signal) are included.

As shown in FIG. 7, the DSP 28 sets the distribution destinations of the left front surround channel signal, the left front height channel signal, the right front surround channel signal, and the right front height channel signal to the output channels according to the sound image localization processing algorithm described later. The left front headrest speaker 10HFL or the right front headrest speaker 10HFR is determined based on the above. Further, the DSP 28 sets the distribution destinations of the left rear surround channel signal, the left rear height channel signal, the right rear surround channel signal, and the right rear height channel signal to the left based on the output channel according to the sound image localization processing algorithm described later. The rear headrest speaker 10HRL or the right rear headrest speaker 10HRR is determined.

The DSP 28 sets the timing at which the sound based on the left front surround channel signal and the right front surround channel signal, which are subjected to the sound image localization processing described later, is output from the left front headrest speaker 10HFL and the right front headrest speaker 10HFR to the left front speaker 10FL and the right. Delay processing for delaying the delay time T1 (an example of the first delay time) from the timing at which the sound is output from the front speaker 10FR is applied to the left front surround channel signal and the right front surround channel signal. This delay processing is an example of the first processing in consideration of the positional relationship between the left front speaker 10FL, the right front speaker 10FR, and the front seat 20.

Further, the DSP 28 sets the timing at which the sound based on the left front height channel signal and the right front height channel signal to be subjected to the sound image localization processing described later is output from the left front headrest speaker 10HFL and the right front headrest speaker 10HFR to the left front speaker 10FL. The left front height channel signal and the right front height channel signal are subjected to delay processing for delaying the delay time T1'(an example of the first delay time) from the timing at which the sound is output from the right front speaker 10FR. This delay processing is an example of the above-mentioned first processing. The left front height channel signal and the right front height channel signal to which the delay processing and the sound image localization processing described later have been performed are mixed with the left front surround channel signal and the right front surround channel signal described above, and the left front headrest speaker 10HFL and the right It is output to the front headrest speaker 10HFR.

Further, the DSP 28 sets the timing at which the sound based on the left rear surround channel signal and the right rear surround channel signal, which are subjected to the sound image localization processing described later, is output from the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR to the left front speaker 10FL. The left rear surround channel signal and the right rear surround channel signal are subjected to delay processing for delaying the delay time T2 (an example of the second delay time) from the timing at which the sound is output from the right front speaker 10FR. This delay processing is an example of the second processing in consideration of the positional relationship between the left front speaker 10FL, the right front speaker 10FR, and the rear seat 24. Further, the delay time T2 is longer than the delay times T1 and T1'.

Further, the DSP 28 sets the timing at which the sound based on the left rear height channel signal and the right rear height channel signal, which are subjected to the sound image localization processing described later, is output from the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR to the left front speaker 10FL. The left rear height channel signal and the right rear height channel signal are subjected to delay processing for delaying the delay time T2'(an example of the second delay time) from the timing at which the sound is output from the right front speaker 10FR. This delay processing is an example of the second processing described above. Further, the delay time T2'is longer than the delay times T1 and T1'. The left rear height channel signal and the right rear height channel signal to which the delay processing and the sound image localization processing described later have been performed are mixed with the left rear surround channel signal and the right rear surround channel signal described above, and the left rear headrest speaker 10HRL and the right It is output to the rear headrest speaker 10HRR.

Further, in the front seat 20, the volume of the sound output from the left front speaker 10FL and the right front speaker 10FR is substantially equal to the volume of the sound output from the left front headrest speaker 10HFL and the right front headrest speaker 10HFR. Adjust each of the above volumes so that Further, in the rear seat 24, the volume of the sound output from the left front speaker 10FL and the right front speaker 10FR is substantially equal to the volume of the sound output from the left rear headrest speaker 10HRL and the left rear headrest speaker 10HRL. Adjust each of the above volumes so that

Further, the DSP 28 performs sound image localization processing on each channel signal of the three-dimensional acoustic signal, and outputs each channel signal of the three-dimensional acoustic signal subjected to the sound image localization processing to the converter unit 32. The DSP 28 performs sound image localization processing on each channel signal of the three-dimensional acoustic signal by using, for example, a binaural filter or the like.

Specifically, as shown in FIG. 6, the DSP 28 displays the sound image of the sound output from the left front headrest speaker 10HFL and the right front headrest speaker 10HFR at the position P1 (first) on the rear left side of the headrest 22 of the front seat 20. The sound image localization process (an example of the first sound image localization process) for localizing to the position) is applied to the left front surround channel signal as the first process described above. Further, the DSP 28 performs sound image localization processing (an example of a third position) for localizing the sound image of the sound output from the left front headrest speaker 10HFL and the right front headrest speaker 10HFR to the position P3 (an example of the third position) above the above-mentioned position P1. An example of the third sound image localization process) is applied to the left front height channel signal as the first process described above.

Further, the DSP 28 is for localizing the sound image of the sound output from the left front headrest speaker 10HFL and the right front headrest speaker 10HFR at the position P1'(an example of the first position) on the rear right side of the headrest 22 of the front seat 20. The sound image localization process (an example of the first sound image localization process) is applied to the right front surround channel signal as the first process described above. Further, the DSP 28 is used for sound image localization for localizing the sound image of the sound output from the left front headrest speaker 10HFL and the right front headrest speaker 10HFR to the position P3'(an example of the third position) above the above-mentioned position P1'. The processing (an example of the third sound image localization processing) is applied to the right front height channel signal as the first processing described above.

Further, the DSP 28 displays the sound image of the sound output from the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR at positions P2 (an example of the second position) different from the rear left side positions P1 and P1'of the headrest 26 of the rear seat 24. ) Is applied to the left rear surround channel signal as the second processing described above, which is the sound image localization process (an example of the second sound image localization process). Further, the DSP28 displays the sound image of the sound output from the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR at a position P4 (an example of a fourth position) different from the above-mentioned positions P3 and P3'above the position P2. The sound image localization process for localization (an example of the fourth sound image localization process) is applied to the left rear height channel signal as the second process described above.

Further, the DSP 28 displays the sound image of the sound output from the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR at positions P2'(second position) different from the rear right positions P1 and P1'of the headrest 26 of the rear seat 24. The sound image localization process (an example of the second sound image localization process) for localizing to (one example) is applied to the right rear surround channel signal as the second process described above. Further, the DSP 28 displays the sound image of the sound output from the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR at a position P4'(a different fourth position) different from the above-mentioned positions P3'and P3'. A sound image localization process (an example of a fourth sound image localization process) for localization to (one example) is applied to the right rear height channel signal as the second process described above.

The converter unit 32 converts each channel signal of the three-dimensional acoustic signal output from the DSP 28 from a digital signal to an analog signal. The converter unit 32 outputs each channel signal of the three-dimensional acoustic signal converted into an analog signal to the amplifier unit 34.

The amplifier unit 34 amplifies each channel signal of the three-dimensional acoustic signal output from the converter unit 32. The amplifier unit 34 outputs each channel signal of the amplified three-dimensional acoustic signal to the speaker group 10 based on the distribution destination determined by the DSP 28.

[2. Operation of acoustic system]
Next, the operation of the acoustic system 2 according to the embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing an operation flow of the acoustic system 2 according to the embodiment.

As shown in FIG. 8, the audio source is reproduced by the audio reproduction unit 12 (S101), and the DSP 28 generates a three-dimensional acoustic signal based on the multi-channel audio signal from the audio reproduction unit 12 (S102).

In this embodiment, the multi-channel acoustic signal is divided into a low-frequency side and a high-frequency side with respect to the rear-channel signal, and the low-frequency side is a surround channel signal and the high-frequency side is a height channel signal. To generate.

Further, as described above, the surround channel signal and the height channel signal reproduced by the user seated on the front seat 20 are used as the front surround channel signal and the front height channel signal, respectively, and similarly, the surround channel reproduced by the user seated on the rear seat 24. The subsequent processing proceeds with the signal and the height channel signal as the rear surround channel signal and the rear height channel signal, respectively.

DSP28 is a three-dimensional acoustic signal left front surround channel signal, right front surround channel signal, left front height channel signal, right front height channel signal, left rear surround channel signal, right rear surround channel signal, left rear height channel signal and Delay processing is performed on the right rear height channel signal (S103).

DSP28 is a three-dimensional acoustic signal left front surround channel signal, right front surround channel signal, left front height channel signal, right front height channel signal, left rear surround channel signal, right rear surround channel signal, left rear height channel signal and Sound image localization processing is performed on the right rear height channel signal (S104). The DSP 28 outputs the three-dimensional acoustic signal subjected to the delay processing and the sound image localization processing described above to the converter unit 32.

The converter unit 32 converts the three-dimensional acoustic signal from the DSP 28 from a digital signal to an analog signal (S105). The converter unit 32 outputs the three-dimensional acoustic signal converted into an analog signal to the amplifier unit 34.

The amplifier unit 34 amplifies the three-dimensional acoustic signal from the converter unit 32 (S106). The amplifier unit 34 outputs the amplified three-dimensional acoustic signal to the speaker group 10 based on the distribution destination determined by the DSP 28. As a result, sound based on the three-dimensional acoustic signal (music based on the audio source, etc.) is output from each speaker of the speaker group 10 (S107), and a three-dimensional sound field (surround sound field) is generated in the vehicle interior of the vehicle 4. Will be done.

At this time, the sound image of the sound output from the left front headrest speaker 10HFL and the right front headrest speaker 10HFR is localized behind and above the headrest 22 of the front seat 20. As a result, for the driver 6 (or the passenger seated in the passenger seat) seated in the front seat 20, sounds can be heard from the rear and above of the headrest 22 of the front seat 20, respectively. As a result, the driver 6 and the like seated on the front seat 20 receive the sound output from the left front speaker 10FL and the right front speaker 10FR and the sound output from the left front headrest speaker 10HFL and the right front headrest speaker 10HFR. Therefore, a feeling of surround sound can be obtained.

Further, the sound image of the sound output from the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR is localized behind and above the headrest 26 of the rear seat 24. As a result, for the passenger 8 seated on the rear seat 24, the sound can be heard from the rear and the upper side of the headrest 26 of the rear seat 24, respectively. As a result, the passenger 8 seated on the rear seat 24 receives the sound output from the left front speaker 10FL and the right front speaker 10FR and the sound output from the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR. You can get a feeling of surround sound.

[3. effect]
As described above, the left front headrest speaker 10HFL and the right front headrest speaker 10HFR are arranged on the headrest 22 of the front seat 20. Further, a left rear headrest speaker 10HRL and a right rear headrest speaker 10HRR are arranged on the headrest 26 of the rear seat 24.

The three-dimensional acoustic signals output to the left front headrest speaker 10HFL and the right front headrest speaker 10HFR are subjected to the first processing in consideration of the positional relationship between the left front speaker 10FL and the right front speaker 10FR and the front seat 20. In addition, virtual sound sources are placed behind the front seat 20 and above it to expand the sense of sound field in a three-dimensional space, and the signals reproduced from the two virtual sound sources are originally banded as a single rear channel signal. By using the divided signals, the phase interference between the output signals of the two virtual sound sources is suppressed, the sound color and sound field feeling become natural, and the front seat 20 is adjusted so that a sufficient surround feeling can be obtained. Will be done. Further, the three-dimensional acoustic signals output to the left rear headrest speaker 10HRL and the right rear headrest speaker 10HRR are subjected to a second process in consideration of the positional relationship between the left front speaker 10FL and the right front speaker 10FR and the rear seat 24. In addition, virtual sound sources are placed behind the rear seat 24 and above it to expand the sound field feeling in a three-dimensional space, and the signals reproduced from the two virtual sound sources are originally banded as a single rear channel signal. By using the divided signals, the phase interference between the output signals of the two virtual sound sources is suppressed, the sound color and the sound field feeling become natural, and the rear seat 24 is adjusted so that a sufficient surround feeling can be obtained. The speaker.

Therefore, regardless of whether the user is seated on the front seat 20 or the rear seat 24, a sufficient surround feeling can be obtained with a more natural sound field feeling.

(Other variants)
Although the acoustic system and the moving body according to one or more aspects have been described above based on the above-described embodiment, the present invention is not limited to the above-described embodiment. As long as it does not deviate from the gist of the present invention, there may be one or a plurality of forms in which various modifications that can be conceived by those skilled in the art are applied to the above-described embodiments, and components constructed by combining components in different embodiments or modifications. It may be included within the scope of the embodiment.

In the above embodiment, the case where the acoustic system 2 is mounted in the vehicle interior of the vehicle 4 has been described, but the present invention is not limited to this, and the acoustic system 2 may be mounted in the interior of various moving bodies such as an aircraft, a train, or a ship. Alternatively, the sound system 2 may be installed in, for example, a living room of a house or a theater room of a commercial facility.

Further, in the above embodiment, the case where the vehicle 4 is an automobile has been described, but the present invention is not limited to this, and various vehicles such as construction machinery and agricultural machinery may be used.

Further, in the above embodiment, the case where the rear seats 24 are arranged in only one row has been described, but the present invention is not limited to this, and the rear seats 24 may be arranged in two or more rows in the front-rear direction.

Further, in the above embodiment, the case where the acoustic system 2 generates a three-dimensional sound field in the vehicle interior of the vehicle 4 has been described, but the present invention is not limited to this, and a two-dimensional sound field is generated in the vehicle interior of the vehicle 4. You may do so. Here, the two-dimensional sound field is a surround sound field having a two-dimensional sound spread.

Further, in the above embodiment, the speaker group 10 is configured to have a plurality of speakers, but the speaker group 10 includes, for example, a rear speaker arranged on the rear door of the vehicle 4 in addition to the plurality of speakers described above. You may have. In this case, for example, low-pitched sound may be output from the rear speaker.

Further, in the above embodiment, the audio source is a recording medium such as a CD, DVD, BD, hard disk, semiconductor memory, etc., but the present invention is not limited to this, and for example, an FM (Frequency Modulation) broadcast wave or the like. May be good.

(Other)
In the above embodiment, each component may be configured by dedicated hardware or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

The following cases are also included in the present disclosure.

(1) Each of the above devices can be specifically realized by a computer system including a microprocessor, a ROM, a RAM, a hard disk unit, a display unit, a keyboard, a mouse, and the like. A computer program is stored in the RAM or the hard disk unit. Each device achieves its function by operating the microprocessor according to a computer program. Here, the computer program is configured by combining a plurality of instruction codes indicating commands to the computer in order to achieve a predetermined function.

(2) A part or all of the components constituting each of the above devices may be composed of one system LSI (Large Scale Integration: large-scale integrated circuit). The system LSI is an ultra-multifunctional LSI manufactured by integrating a plurality of components on one chip, and specifically, is a computer system including a microprocessor, a ROM, a RAM, and the like. .. A computer program is stored in the ROM. The system LSI achieves its function by loading a computer program from the ROM into the RAM by the microprocessor and performing operations such as calculations according to the loaded computer program.

(3) A part or all of the constituent elements constituting each of the above devices may be composed of an IC card or a single module that can be attached to and detached from each device. An IC card or module is a computer system composed of a microprocessor, ROM, RAM, and the like. The IC card or module may include the above-mentioned super multifunctional LSI. The IC card or module achieves its function by operating the microprocessor according to the computer program. This IC card or this module may have tamper resistance.

(4) The present disclosure may be realized by the method shown above. Further, these methods may be realized by a computer program realized by a computer, or may be realized by a digital signal composed of a computer program.

Further, in the present disclosure, a computer program or a digital signal is recorded on a computer-readable recording medium such as a flexible disk, a hard disk, a CD-ROM, an MO, a DVD, a DVD-ROM, a DVD-RAM, a BD, or a semiconductor memory. It may be realized by a thing. Further, it may be realized by a digital signal recorded on these recording media.

Further, in the present disclosure, a computer program or a digital signal may be transmitted via a telecommunication line, a wireless or wired communication line, a network typified by the Internet, data broadcasting, or the like.

Further, the present disclosure is a computer system including a microprocessor and a memory, in which the memory stores a computer program, and the microprocessor may operate according to the computer program.

It may also be implemented by another independent computer system by recording the program or digital signal on a recording medium and transferring it, or by transferring the program or digital signal via a network or the like.

(5) The above-described embodiment and the above-described modification may be combined.

The acoustic system according to the present disclosure can be applied to, for example, an in-vehicle acoustic system mounted on a vehicle.

2 Sound system 4 Vehicle 6 Driver 8 Passenger 10 Speaker group 10FL Left front speaker 10FR Right front speaker 10HFL Left front headrest speaker 10HFR Right front headrest speaker 10HRL Left rear headrest speaker 10HRR Right rear headrest speaker 12 Audio playback unit 14 Control unit 16 Left front door 18 Right front door 20 Front seats 22, 26 Headrest 24 Rear seats 28 DSP
32 Converter section 34 Amplifier section

Claims (8)

An acoustic system for playing an audio source in a room in which a front seat having a first headrest and a rear seat having a second headrest for the user to sit are arranged side by side.
A front speaker arranged in front of the front seat in the room,
The first headrest speaker arranged on the first headrest,
A second headrest speaker arranged on the second headrest,
A control unit that generates an acoustic signal based on the audio source and outputs the generated audio signal to the front speaker, the first headrest speaker, and the second headrest speaker is provided.
The control unit
The acoustic signal is subjected to the first processing in consideration of the positional relationship between the front speaker and the front seat, and the acoustic signal subjected to the first processing is output to the first headrest speaker.
An acoustic system that applies a second process to the acoustic signal in consideration of the positional relationship between the front speaker and the rear seat, and outputs the acoustic signal to which the second process has been applied to the second headrest speaker. The first process is a process for delaying the timing at which the sound is output from the first headrest speaker by the first delay time from the timing at which the sound is output from the front speaker.
In the second process, the timing at which the sound is output from the second headrest speaker is longer than the timing at which the sound is output from the front speaker, and the second delay time is longer than the first delay time. The acoustic system according to claim 1, which is a process for delaying only. The control unit
As the first process, the acoustic signal is subjected to a first sound image localization process for localizing a sound image of a sound output from the first headrest speaker to a first position behind the first headrest. The first channel signal to which the first channel signal included in the above is applied and the first sound image localization process has been applied is output to the first headrest speaker.
As the second process, a second process for localizing the sound image of the sound output from the second headrest speaker to a second position behind the second headrest, which is different from the first position. The second channel signal included in the acoustic signal is subjected to the sound image localization process, and the second channel signal subjected to the second sound image localization process is output to the second headrest speaker. Or the acoustic system according to 2. The control unit
As the first process, the acoustic signal is subjected to a third sound image localization process for localizing the sound image of the sound output from the first headrest speaker to a third position above the first headrest. The first channel signal subjected to the first sound image localization process and the third channel signal subjected to the third sound image localization process are applied to the third channel signal included in the first. Output to the headrest speaker of
As the second process, a fourth process for localizing the sound image of the sound output from the second headrest speaker to a fourth position above the second headrest, which is different from the third position. The sound image localization process is applied to the fourth channel signal included in the acoustic signal, and the second channel signal subjected to the second sound image localization process and the second channel signal subjected to the fourth sound image localization process. The acoustic system according to claim 3, wherein the channel signal of No. 4 is output to the second headrest speaker. The acoustic system according to any one of claims 1 to 4, wherein the acoustic signal is a three-dimensional acoustic signal for generating a three-dimensional sound field in the room. The three-dimensional acoustic signal is a signal that divides the frequency band of a predetermined channel signal of the acoustic signal into a channel that localizes the high frequency side upward and a channel that localizes the low frequency side downward. Item 5. The acoustic system according to item 5. The acoustic system according to any one of claims 1 to 6, wherein the room is a room of a moving body that moves with the user on board. A moving body that moves with the user on board
A moving body equipped with the acoustic system according to any one of claims 1 to 7, which is mounted in the room of the moving body.

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