JP2013211625A - On-vehicle acoustic processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform correction processing without increasing noises even in the case where a frequency band becomes different in accordance with the type of a sound source when simultaneously reproducing two different sound sources within a compartment, and to more effectively cancel influences of the other sound source in the case where priorities are set.SOLUTION: On the basis of sound source analysis information supplied from frequency analysis means 104, 105 for analyzing two types of sound sources to be reproduced within a vehicle, sound source type information supplied from sound source type analysis means 106 for analyzing the two sound source types and priorities supplied from user side priority setting means 103 for setting priorities by a user, correction characteristics are calculated by correction characteristic calculating means 107 and the correction characteristics are set in front-seat correction characteristic setting means 108 and rear-seat correction characteristic setting means 109. Therefore, correction characteristics suitable for a front-seat sound source and a rear-seat sound source, respectively, are added and outputted.

Description

  The present invention relates to an in-vehicle acoustic processing apparatus that performs correction processing of an acoustic signal reproduced in a vehicle in consideration of the mutual influence of two sound sources when two types of sound sources are reproduced simultaneously in a vehicle interior.

  In Patent Document 1 below, when two types of sound sources are reproduced at the same time in a vehicle, the two types of sound sources are analyzed by frequency analysis means so that the sensory level for each frequency band of the two sound sources is the same. Discloses a technique for performing correction processing.

JP 2008-203716 A

  According to the technique disclosed in Patent Document 1, when two types of sound sources are reproduced at the same time in the vehicle interior, it is possible to minimize the influence of each other's sound sources at the trial listening position. However, if there is a large difference between the two types of sound sources, for example, sound sources with different frequency bands, such as voice and music, the same processing must be performed. There was a problem that the noise increased by performing the correction. Further, even when the two types of sound sources are sound sources in the same frequency band, the mutual influence cannot be completely eliminated.

  In order to solve the above problem, the present invention can perform correction processing without increasing noise even when the frequency band differs depending on the type of sound source, and when priority is set, the other It is an object of the present invention to provide an in-vehicle acoustic processing device that can eliminate the influence more effectively.

  In order to achieve the above object, the on-vehicle acoustic processing device of the present invention is different from the acoustic signal for the front seat and the rear acoustic signal that are reproduced simultaneously for the front seat and the rear seat in the same vehicle interior space. One of the acoustic signals for the seat is used as a sound source and the other is used as noise, and a sensory level that is attenuated by the noise signal that is the other noise of the acoustic signal that is one of the sound sources is calculated. Correction characteristic calculation means for outputting as a correction characteristic for correcting an acoustic signal to be a sound source.

  With this configuration, it is possible to reduce the influence of each other's sound source without increasing noise even when the types of the two sound sources that are simultaneously reproduced in the passenger compartment are different.

  In addition, a priority setting unit that sets priorities of the front-seat acoustic signal and the rear-seat acoustic signal is provided, and the correction characteristic calculation unit uses the higher-priority acoustic signal as an acoustic signal. And

  With this configuration, by setting the priority, one (front seat sound source or rear seat sound source) can more effectively eliminate the influence of the other acoustic signal.

  Further, the correction characteristic calculating means sets the priority of the front seat acoustic signal and the rear seat acoustic signal based on the sound source type information of the front seat acoustic signal and the rear seat acoustic signal, The higher acoustic signal is set as an acoustic signal that is a sound source. Alternatively, the correction characteristic calculation means sets a higher priority for the narrower frequency band of the front seat acoustic signal and the rear seat acoustic signal, and the higher priority acoustic signal is the one of the sound sources. The acoustic signal is as follows.

  Also with these configurations, the priority is set in the same manner as described above, and the influence of the other acoustic signal can be more effectively eliminated in one (front seat sound source or rear seat sound source).

  The in-vehicle acoustic processing device of the present invention has an effect of reducing the influence of each other's sound source without increasing noise, even when the types of two sound sources reproduced simultaneously in the passenger compartment are different. Also, the priority setting allows one (front seat sound source or rear seat sound source) to more effectively eliminate the influence of the other sound source.

The block diagram which shows an example of a structure of the vehicle-mounted sound processing apparatus in embodiment of this invention Sensory level characteristic diagram in a noise-free environment according to an embodiment of the present invention Sensory level characteristic diagram under noise environment in the embodiment of the present invention The characteristic view which shows an example of correction | amendment of the sensory level under the noise environment in embodiment of this invention The flowchart which shows the flow of a process of the correction characteristic calculation means 107. In the embodiment of the present invention, a situation explanatory diagram when different sound sources are reproduced simultaneously in the same vehicle interior space

  Hereinafter, an in-vehicle acoustic processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. The embodiment of the present invention described below shows a preferred specific example of the present invention. The numerical values, shapes, components, arrangement of components, connection forms, and the like shown in this embodiment are merely examples, and are not intended to limit the present invention. The invention is limited only by the claims. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims are not necessarily required to achieve the object of the present invention, but are described as constituting more preferable embodiments. The

  FIG. 1 is a diagram illustrating an example of the configuration of an in-vehicle acoustic processing apparatus according to an embodiment of the present invention. 1 includes a front seat sound source device 101, a rear seat sound source device 102, a user-side priority setting means 103, a front seat sound source frequency analysis means 104, and a rear seat sound source frequency analysis means 105. A sound source type analyzing means 106, a correction characteristic calculating means 107, a front seat correction characteristic setting means 108, a rear seat correction characteristic setting means 109, a speaker-specific front seat signal output terminal 110, and a speaker-specific rear seat signal output terminal 111. Yes.

  The front seat sound source device 101 and the rear seat sound source device 102 are audio output devices such as a CD (Compact Disc) and a DVD (Digital Versatile Disc), or tuner devices such as a TV and a radio. (Electrical signal) is output.

  Further, the front seat sound source device 101 and the rear seat sound source device 102 have a function of outputting the type information of the sound source being output and the set volume value.

  Here, the sound source type information is the type of sound source output from a sound source device such as BD (Blu-ray), DVD, CD, USB (Universal Serial Bus), AUX, FM radio, AM radio, terrestrial digital, and navigation sound. Refers to information. BD, DVD, USB, AUX, and the like can also include audio (music) format information such as MPEG2 (Moving Picture Experts Group phase 2), AC3 (Audio Code number 3), LPCM (Linear Pulse Code Modulation).

  The user-side priority setting means 103 has an interface function composed of buttons, switches, and the like that can be operated by the user, and selects the front seat sound source priority, the rear seat sound source priority, automatic, etc. Output degree information.

  The 104 to 109 typically include a CPU, a ROM, and a RAM, and the CPU executes a computer program stored in advance in the ROM using the RAM.

  The front seat sound source frequency analysis means 104 is connected to the front seat sound source device 101, analyzes the frequency characteristics of music and audio signals supplied from the front seat sound source device 101, and analyzes information (frequency characteristics) of each frequency band. Is output to the correction characteristic calculation means 107.

  The rear seat sound source frequency analysis means 105 is connected to the rear seat sound source device 102, analyzes the frequency characteristics of music and audio signals supplied from the rear seat sound source device 102, and analyzes information (frequency characteristics) of each frequency band. Is output to the correction characteristic calculation means 107.

  The sound source type analyzing means 106 is connected to the front seat sound source device 101 and the rear seat sound source device 102, and the sound source type information and volume value (VOL information) supplied from the front seat sound source device 101 and the rear seat sound source device 102. ) Is output to the correction characteristic calculation means 107.

  The sound source type analyzing unit 106 is connected to the front seat sound source frequency analyzing unit 104 and the rear seat sound source frequency analyzing unit 105 when the sound source type information cannot be obtained from the front seat sound source device 101 and the rear seat sound source device 102. Thus, the sound source type can be determined from the frequency characteristics supplied from the front seat sound source frequency analyzing means 104 and the rear seat sound source frequency analyzing means 105, and the sound source type information can be output to the correction characteristic calculating means 107.

  The correction characteristic calculation means 107 is connected to the user-side priority setting means 103, the front seat sound source frequency analysis means 104, the rear seat sound source frequency analysis means 105, and the sound source type analysis means 106. Processing is performed based on the supplied priority information. If the priority is automatic, the priority is first selected based on the sound source type information supplied from the sound source type analyzing means 106. As a priority, since a sound source with a narrow frequency band (for example, sound) has little influence on the other sound source, the priority of the sound source with a narrow frequency band is set high. For example, a sound source of almost audio signals such as navigation voice, AM radio, and traffic information can be set higher in priority than a sound source estimated to be almost music such as CD and USB.

  Further, the correction characteristic calculation means 107 determines the audible sound source based on the frequency characteristics supplied from the front seat sound source frequency analysis means 104 and the rear seat sound source frequency analysis means 105 after the priority information is determined. The correction characteristic is calculated and output so as not to be affected by the sound source on the side where is not prioritized.

  The correction characteristic calculation unit 107 performs processing for the entire band when the sound source to be preferentially corrected is a sound source with a narrow frequency band such as voice based on the sound source type information supplied from the sound source type analysis unit 106. In addition, it has a function of calculating and outputting correction characteristics so that correction processing is performed only in a band where the signal level is actually high.

  The front seat correction characteristic setting unit 108 and the rear seat correction characteristic setting unit 109 have a function of performing a correction process based on the correction characteristic supplied from the correction characteristic calculation unit 107 and outputting a sound and a music signal (electric signal).

  The front-seat signal output terminal 110 for each speaker and the rear-seat signal output terminal 111 for each speaker are set for each sound source with audio and music signals supplied from the front seat correction characteristic setting means 108 and the rear seat correction characteristic setting means 109, respectively. Output to other speakers.

  Here, a brief description will be given of correction processing when two sound sources are simultaneously reproduced in the passenger compartment. When two sound sources are played back simultaneously, there is no correlation between the two sound sources. Therefore, when one of the sound sources is auditioned, the other sound source becomes noise. Correction processing is performed to eliminate the effects of noise, but processing that keeps the sensory level constant is performed. The sensory level is defined by the difference between the input sound pressure level and the minimum audible level of the band in the amplitude frequency characteristic when a certain acoustic signal is presented. FIG. 2 is an example showing a sensory level when there is no noise, and shows a case where a certain acoustic signal is presented with an amplitude frequency characteristic indicated by a solid line and a minimum audible level is a dotted line. The sensory level when there is no noise is represented by the hatched portion in FIG. However, the sensory level may be a difference between the input sound pressure level and a minimum audible level of the band multiplied by a constant in the amplitude frequency characteristic when a certain acoustic signal is presented.

  FIG. 3 shows a case where noise exists with an amplitude frequency characteristic represented by a broken line, and the sensory level at that time is as shown by the hatched portion in FIG. 3, which is a sensory level compared to the case where there is no noise. Decrease. Therefore, in order to correct this decrease in the sensory level, the frequency characteristic of the acoustic signal is changed by the correction level in FIG.

Next, the processing flow of the correction characteristic calculation unit 107 will be described with reference to the flowchart of FIG. First, the correction characteristic calculation unit 107 determines whether or not the priority information supplied from the user-side priority setting unit 103 is automatic (Step S501). If it is not automatic (No in step S501), the process proceeds to step S502, and the correction characteristic calculation unit 107 determines whether the priority is the front seat.
If the priority is the front seat (Yes in step S502), the front seat sound source is used as a sound source and the rear seat sound source is handled as noise (step S504). On the other hand, if the priority is the rear seat in step S502 (No), the rear seat sound source is treated as a sound source and the front seat sound source is treated as noise (step S505).

  In step S501, when the priority information is automatic (Auto) (Yes), the correction characteristic calculation unit 107 determines that the band of the front seat sound source received from the front seat sound source frequency analysis unit 104 is the rear seat sound source frequency analysis unit 105. It is determined whether it is narrower than the band of the rear seat sound source received from (step S503). When the band of the front seat sound source is narrower (Yes in step S503), since the influence on the sound source of the rear seat is small, the correction characteristic calculation unit 107 sets the priority of the front seat sound source high (step S504). . On the other hand, if the band of the rear seat sound source is narrower in step S503 (No), since the influence on the front seat sound source is small, the correction characteristic calculation means 107 sets the priority of the rear seat sound source high ( Step S505). Then, the process proceeds to step S506.

  In step S506, the correction characteristic calculation unit 107 calculates the noise characteristic at the listening point (the frequency characteristic of the noise signal shown in FIG. 3). Here, when the front seat sound source is noisy, a frequency characteristic that a signal reproduced from the front seat speaker is transmitted to the rear seat listening point in advance is stored in a memory (not shown in FIG. 1). The frequency characteristic of the noise signal is calculated by convolving the characteristic with the front seat sound source characteristic received from the front seat sound source frequency analyzing means 104. Similarly, when the rear seat sound source is noisy, a frequency characteristic that a signal reproduced from the rear seat speaker is transmitted to the front seat listening point in advance is stored in a memory (not shown in FIG. 1), and the frequency The frequency characteristic of the noise signal is calculated by convolving the characteristic with the rear seat sound source characteristic received from the rear seat sound source frequency analyzing means 105. Then, the process proceeds to step S507.

  In step S507, the correction characteristic calculation unit 107 calculates a sound source characteristic (frequency characteristic of the acoustic signal shown in FIG. 3) at the listening point. Here, when the front seat sound source is a sound source, a frequency characteristic in which a signal reproduced from the front seat speaker is transmitted to the front seat listening point in advance is stored in a memory (not shown in FIG. 1). The frequency characteristic of the acoustic signal is calculated by convolving the characteristic with the front seat sound source characteristic received from the front seat sound source frequency analyzing means 104. Similarly, when the rear seat sound source is a sound source, a frequency characteristic in which a signal reproduced from the rear seat speaker is transmitted to the rear seat listening point in advance is stored in a memory (not shown in FIG. 1), and the frequency is stored. The frequency characteristic of the acoustic signal is calculated by convolving the characteristic with the rear seat sound source characteristic received from the rear seat sound source frequency analyzing means 105. Then, the process proceeds to step S508.

  In step S508, the frequency band in which the sound actually exists is calculated from the frequency characteristics of the acoustic signal calculated in step S507. Here, when the acoustic signal is voice, AM radio, or the like, the frequency characteristic of the acoustic signal takes a smaller value in the low range and the high range than in the middle range. Therefore, the lower limit and upper limit of the frequency that exceeds a certain amount (eg, -20 dB) below the mid-range level are calculated, the frequency band of the acoustic signal is calculated between them, and the frequency characteristics within that band are calculated as the sound source characteristics. To do. Then, the process proceeds to step S509.

  In step S509, a sound source correction characteristic is calculated from the noise characteristic calculated in step S506 and the sound source characteristic calculated in step S508. Here, the sensory level in FIG. 4 is the frequency characteristic of the acoustic signal calculated in step S507, and the noise signal in FIG. 4 is the noise characteristic calculated in step S506. The sensory level attenuated by the noise signal is calculated, and the attenuated sensory level is used as a correction characteristic.

  Next, in step S510, it is determined whether the correction characteristic calculated in step S509 is not zero. If it is not 0 (YES in step S510), the process proceeds to step S511, and the noise correction characteristic is set to 0. If 0 (NO in step S510), the process proceeds to step S512, and noise correction characteristics are calculated. Here, when the sound source correction characteristic is 0, the noise characteristic is very small relative to the sound source characteristic, and the sense level does not vary depending on the presence or absence of noise. However, a range in which the sensory level does not vary is calculated to obtain noise correction characteristics. In step S513, the sound source correction characteristic and the noise correction characteristic are output, and the correction characteristic calculation unit 107 ends the processing flow.

  In step S503, the band of the front-seat sound source and the rear-seat sound source is compared to set the priority, but the priority is selected based on the sound source type information supplied from the sound source type analysis unit 106. May be.

  Next, a specific example of the acoustic signal output realized by using the in-vehicle acoustic processing device according to the embodiment of the present invention will be described.

  FIG. 6 shows an example in which different sound sources are played in the front seat and the rear seat in the passenger compartment of the vehicle 1000. The front seat speakers 1300a and 1300b reproduce the signal obtained from the speaker-specific front seat signal output terminal 110 for the front seat 1100. The rear-seat speakers 1400a and 1400b reproduce the signals obtained from the rear-seat signal output terminals 111 for the rear seats 1200. In this way, when two different sound sources are reproduced in the same space, the sound of the rear seat sound source becomes noise in the front seat 1100 and the sound of the front seat sound source becomes noise in the rear seat 1200, thereby preventing the trial listening.

  In the situation shown in FIG. 6, the priority is first determined by the user-side priority setting means 103, and it is determined which of the front seat 1100 and the rear seat 1200 is prioritized. When the user selects automatic, priority is determined in the correction characteristic calculation unit 107 based on the sound source type information supplied from the sound source type analysis unit 106.

  For example, when priority is given to the front seat 1100 as a priority, the sound reproduced from the rear seat speakers 1400a and 1400b and transmitted to the front seat 1100 is treated as noise, and the sensory level at the front seat 1100 as shown in FIG. Perform the correction.

  If the signal reproduced from the front seat speakers 1300a and 1300b is a signal having a narrow frequency band such as voice, the sensory level is corrected only in the frequency band in which the signal exists based on the sound source type analysis information. .

  In addition, when the signal reproduced from the rear seat speakers 1400a and 1400b is small enough that the front seat 1100 does not need to be corrected, it is necessary to correct the sensory level of the front seat 1100. The rear seat sound source is corrected to the level of.

  As described above, the on-vehicle acoustic processing device of the present invention reduces the influence of each other's sound source without increasing noise even when the types of two sound sources that are simultaneously reproduced in the passenger compartment are different. can do. Further, the influence of the other sound source can be eliminated in one (front seat sound source or rear seat sound source) by setting the priority.

  In the present embodiment, the on-vehicle sound processing apparatus has been described as including the front seat sound source device 101 and the rear seat sound source device 102, but the front seat sound source device 101 installed outside is not included in the configuration. The front seat sound source and the rear seat sound source output from the rear seat sound source device 102 may be input.

  The in-vehicle acoustic processing apparatus of the present invention has a sensory level of an acoustic signal that a listener listens to, either in the front seat or the rear seat, even when two different sound sources are reproduced in the same vehicle interior space. It has the effect that it can be kept constant, and is useful as a vehicle-mounted device such as a vehicle-mounted audio device.

DESCRIPTION OF SYMBOLS 100 Vehicle-mounted sound processing apparatus 101 Front seat sound source device 102 Rear seat sound source device 103 User-side priority setting means 104 Front seat sound source frequency analysis means 105 Rear seat sound source frequency analysis means 106 Sound source type analysis means 107 Correction characteristic calculation means 108 Front seat Correction characteristic setting means 109 Rear seat correction characteristic setting means 110 Speaker-specific front seat signal output terminal 111 Speaker-specific rear seat signal output terminal 1000 Vehicle 1100 Front seat 1200 Rear seat 1300a, 1300b Front seat speaker 1400a, 1400b Rear seat speaker

Claims (4)

For different acoustic signals that are reproduced simultaneously for the front seat and the rear seat in the same vehicle interior space, one of the front seat acoustic signal and the rear seat acoustic signal is used as a sound source and the other is a noise. As described above, a sensory level that is attenuated by a noise signal that is the other noise of the sound signal that is the one sound source is calculated, and the attenuated sensory level is corrected to correct the sound signal that is the one sound source. A vehicle-mounted acoustic processing apparatus including correction characteristic calculation means for outputting as a characteristic. Priority setting means for setting priorities of the front-seat acoustic signal and the rear-seat acoustic signal is provided, and the correction characteristic calculation means serves as the one of the sound sources having the higher priority acoustic signal. The on-vehicle acoustic processing device according to claim 1, wherein the on-vehicle acoustic processing device is an acoustic signal. The correction characteristic calculation means sets priorities of the front seat acoustic signal and the rear seat acoustic signal based on sound source type information of the front seat acoustic signal and the rear seat acoustic signal. The in-vehicle acoustic processing apparatus according to claim 1, wherein the higher priority acoustic signal is an acoustic signal that is a sound source on the one side. The correction characteristic calculating means sets a higher priority for the narrower frequency band of the front seat acoustic signal and the rear seat acoustic signal, and the higher priority acoustic signal is The in-vehicle sound processing apparatus according to claim 1, wherein the sound signal is a sound source that is a sound source.

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