Sound Field Control Device

Abstract

To provide a sound field control device capable of appropriately controlling the sound field in a vehicle.SOLUTION: A sound field control device 10 includes: multiple speakers 40L, 40R installed in a vehicle; a signal processing unit 28 that performs a series of signal processing to add sound field effects to the sound reproduced from the multiple speakers 40L, 40R in the process of generating multiple channel sound signals representing the engine sound and supplied to multiple speakers 40L, 40R; and a control unit 30 that controls signal processing by the signal processing unit 28 based on vehicle driving conditions.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a sound field control device. [Background technology]

[0002] Conventionally, there has been disclosed an in-vehicle acoustic control device that detects an engine ignition signal, generates a sine wave signal synchronized with the engine rotation period, and reproduces the signal from a speaker in the vehicle cabin (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-80790 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the in-vehicle acoustic control device of Patent Document 1 simply reproduces engine sound using a sine wave signal synchronized with the rotation period of the engine, and it is difficult to appropriately control the sound field inside the vehicle.

[0005] Therefore, the present disclosure provides a sound field control device that can easily and appropriately control the sound field inside a vehicle. [Means for solving the problem]

[0006] A sound field control device according to one embodiment of the present disclosure includes a plurality of speakers provided in a vehicle, a signal processing unit that performs signal processing to impart a sound field effect to sounds reproduced from the plurality of speakers in a process of generating multi-channel sound signals representing at least one of an engine sound, an engine exhaust sound, and a motor sound and that are supplied to the plurality of speakers, and a control unit that controls the signal processing by the signal processing unit based on the driving state of the vehicle. Effect of the Invention

[0007] The sound field control device of the present disclosure makes it easy to appropriately control the sound field inside a vehicle. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing a functional configuration of a sound field control device according to the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a sound field control device according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiment will be specifically described with reference to the drawings.

[0010] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, the arrangement and connection of the components, steps, and the order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in the independent claims showing the highest concept are described as optional components.

[0011] In addition, each drawing is a schematic diagram and is not necessarily a precise illustration. In addition, in each drawing, the same components are denoted by the same reference numerals.

[0012] (First embodiment) FIG. 1 is a block diagram showing a functional configuration of a sound field control device 10 according to the first embodiment.

[0013] As shown in Fig. 1, the sound field control device 10 is a device that performs signal processing to impart a sound field effect to sounds reproduced from a plurality of speakers 40L, 40R provided in a vehicle (not shown) based on the driving state of the vehicle, and controls the sound field in the vehicle. For example, the vehicle is a vehicle that runs by driving wheels, such as an automobile or a train. Specifically, the vehicle is, for example, an electric vehicle powered by a motor, a hybrid vehicle equipped with two or more power sources, or a vehicle powered by an engine.

[0014] In this embodiment, the sound field control device 10 applies a sound field effect to engine sound collected in the vehicle and outputs the sound from multiple speakers 40L, 40R. In this embodiment, the engine sound includes intake sound, sound in the engine room, exhaust sound, and sound outside the vehicle. For example, the sound field control device 10 may apply a sound field effect to motor sound collected in the vehicle and output the sound from multiple speakers 40L, 40R.

[0015] The sound field control device 10 includes a plurality of microphones 12, 14, 16, 18, a plurality of filters 20, 22, 24, 26, a signal processing unit 28, a control unit 30, an accelerator sensor 32, a shift sensor 34, a speed sensor 36, a memory 38, and a plurality of speakers 40L, 40R.

[0016] The multiple microphones 12, 14, 16, and 18 are arranged at positions where they can pick up engine sounds. For example, the microphone 12 is arranged at a position where it can pick up intake sounds, the microphone 14 is arranged at a position where it can pick up sounds inside the engine room, the microphone 16 is arranged at a position where it can pick up exhaust sounds, and the microphone 18 is arranged at a position where it can pick up sounds outside the vehicle.

[0017] The filters 20, 22, 24, 26 are provided corresponding to the microphones 12, 14, 16, 18. Each of the filters 20, 22, 24, 26 selects and outputs a predetermined component from the electrical signal obtained from the corresponding one of the microphones 12, 14, 16, 18. For example, the filter 20 selects and outputs a component having characteristics of an intake sound from the electrical signal obtained from the microphone 12. Also, for example, the filter 22 selects and outputs a component having characteristics of a sound in the engine room from the electrical signal obtained from the microphone 14. Also, for example, the filter 24 selects and outputs a component having characteristics of an exhaust sound from the electrical signal obtained from the microphone 16. Also, for example, the filter 26 selects and outputs a component having characteristics of a sound outside the vehicle from the electrical signal obtained from the microphone 18.

[0018] The signal processing unit 28 performs signal processing to impart a sound field effect to the sound reproduced from the multiple speakers 40L, 40R in the process of generating a multi-channel sound signal (electrical signal) representing the engine sound and supplied to the multiple speakers 40L, 40R. In this embodiment, the multi-channel sound signal is a two-channel sound signal. In this embodiment, the signal processing includes a sound image localization process for localizing the sound image of the sound reproduced from the multiple speakers 40L, 40R at a predetermined position, and a filter process for controlling the correlation coefficient of the sound reproduced from the multiple speakers 40L, 40R. For example, the predetermined position is a target position or area for localizing the sound image of the sound reproduced from the multiple speakers 40L, 40R, and is determined in advance. The signal processing unit 28 has a mixer 42, a filter 44, and a processing unit 46.

[0019] The mixer 42 synthesizes the electric signals that have passed through the multiple filters 20, 22, 24, 26 to generate and output two-channel sound signals, one for left and one for right. The mixer 42 also performs a sound image localization process in the process of generating the two-channel sound signals. Specifically, for example, under the control of the control unit 30, the mixer 42 performs a process for localizing the sound images of the sounds reproduced from the multiple speakers 40L, 40R for each sound source, such as intake sound, sound in the engine room, exhaust sound, and sound outside the vehicle, at a target position or area. The mixer 42 has multiple amplifiers 48, 50, 52, 54, multiple sound image localization processing units 56, 58, 60, 62, and multiple signal lines 64, 66.

[0020] The amplifiers 48, 50, 52, 54 are gain-controllable amplifiers and are provided corresponding to the filters 20, 22, 24, 26. Each of the amplifiers 48, 50, 52, 54 amplifies and outputs an electric signal that has passed through a corresponding one of the filters 20, 22, 24, 26. For example, the amplifier 48 is a device for controlling the intensity of intake sound in the sound reproduced from the speakers 40L, 40R. For example, the amplifier 50 is a device for controlling the intensity of sound in the engine room in the sound reproduced from the speakers 40L, 40R. For example, the amplifier 52 is a device for controlling the intensity of exhaust sound in the sound reproduced from the speakers 40L, 40R. For example, the amplifier 54 is a device for controlling the intensity of sound outside the vehicle in the sound reproduced from the speakers 40L, 40R.

[0021] The plurality of sound image localization processing units 56, 58, 60, 62 perform sound image localization processing to generate left channel signals and right channel signals for obtaining a target sound image localization. The plurality of sound image localization processing units 56, 58, 60, 62 are provided corresponding to the plurality of amplifiers 48, 50, 52, 54. Each of the plurality of sound image localization processing units 56, 58, 60, 62 generates a left channel signal and a right channel signal for obtaining a target sound image localization from an electric signal output from a corresponding one of the plurality of amplifiers 48, 50, 52, 54. The plurality of sound image localization processing units 56, 58, 60, 62 outputs the generated left channel signal to a signal line 64 and outputs the generated right channel signal to a signal line 66. The left channel signals output from the multiple sound image localization processing units 56, 58, 60, and 62 are added together on a signal line 64 to become a sound signal, and the right channel signals output from the multiple sound image localization processing units 56, 58, 60, and 62 are added together on a signal line 66 to become a sound signal.

[0022] For example, each of the multiple sound image localization processing units 56, 58, 60, 62 distributes an electric signal output from a corresponding one of the multiple amplifiers 48, 50, 52, 54 into two left and right channel signals and adjusts the phases of these signals to generate a left channel signal and a right channel signal based on an instruction from the control unit 30. The distribution ratio when distributing to the two left and right channels and the amount of phase adjustment of the two left and right channel signals are set in advance according to a target sound image position or area, and are instructed by the control unit 30 to the multiple sound image localization processing units 56, 58, 60, 62.

[0023] Also, for example, a left channel filter coefficient sequence and a right channel filter coefficient sequence for sound image localization are provided in advance in accordance with a target sound image position or area, and are provided from the control unit 30 to the multiple sound image localization processing units 56, 58, 60, 62. Each of the multiple sound image localization processing units 56, 58, 60, 62 convolves the left channel filter coefficient sequence with an electric signal output from a corresponding one of the multiple amplifiers 48, 50, 52, 54 to generate a left channel signal, and convolves the right channel filter coefficient sequence with the electric signal to generate a right channel signal. The configuration of the multiple sound image localization processing units 56, 58, 60, 62 may be selected in consideration of the required quality of the sounds reproduced from the multiple speakers 40L, 40R, the cost, etc.

[0024] The filter 44 is a filter that performs filtering. The filter 44 convolves two sets of filter coefficient strings provided by the control unit 30 with two-channel sound signals obtained from the mixer 42, and generates and outputs two-channel sound signals. In this manner, for example, the filter 44 is a pair of convolution calculators. In this embodiment, the filter 44 changes the correlation coefficient between the two ears of the sounds reproduced from the multiple speakers 40L, 40R and heard by the driver, and adjusts the sense of spread of the sound.

[0025] The control unit 30 controls the signal processing by the signal processing unit 28 based on the driving state of the vehicle. For example, the control unit 30 adjusts the sense of spread of the sound reproduced from the multiple speakers 40L, 40R by adjusting the correlation coefficient of two sets of filter coefficient sequences provided to the filter 44. Specifically, for example, when the sound image of the sound reproduced from the multiple speakers 40L, 40R is to be dispersed over a wide range, two sets of filter coefficient sequences, both of which correspond to flat filter characteristics and have low correlation, are provided from the control unit 30 to the filter 44. On the other hand, for example, when the sound image of the sound reproduced from the multiple speakers 40L, 40R is to be concentrated in a narrow range, two sets of filter coefficient sequences, both of which correspond to flat filter characteristics and have high correlation, are provided from the control unit 30 to the filter 44.

[0026] The control unit 30 determines the driving state of the vehicle based on the measurement results of the accelerator sensor 32, the shift sensor 34, the speed sensor 36, etc. The accelerator sensor 32 is a sensor for detecting the amount of depression of the accelerator pedal of the vehicle. The shift sensor 34 is a sensor for detecting the position of the shift lever of the vehicle. The speed sensor 36 is a sensor for detecting the speed of the vehicle.

[0027] The control unit 30 performs a process of setting the gains of the amplifiers 48, 50, 52, and 54 based on the identified operating state. The control unit 30 also performs a process of setting sound image localization control parameters such as the distribution ratio and phase adjustment amount or filter coefficient sequence described above for the sound image localization processing units 56, 58, 60, and 62 based on the identified operating state. The control unit 30 also performs a process of setting a filter coefficient sequence for the filter 44 based on the identified operating state.

[0028] The memory 38 stores combinations of gains, sound image localization control parameters, and filter coefficient strings for the amplifiers 48, 50, 52, 54 in association with each of a plurality of predetermined operating states. When the control unit 30 identifies an operating state, it reads out the gains, sound image localization control parameters, and filter coefficient strings associated with the identified operating state from the memory 38 and sets the gains, sound image localization control parameters, and filter coefficient strings for the amplifiers 48, 50, 52, 54, etc.

[0029] The processing unit 46 is a circuit that performs predetermined signal processing on the two-channel sound signals output from the filter 44, and outputs the two-channel sound signals that have been subjected to the signal processing to the left and right two-channel speakers 40L and 40R. The processing unit 46 has a plurality of attenuators 66L, 66R, a plurality of high-pass filters 68L, 68R, a plurality of low-pass filters 70L, 70R, a plurality of sound-insulating filters 72L, 72R, and a plurality of dynamic filters 74L, 74R. The attenuator 66L, the high-pass filter 68L, the low-pass filter 70L, the sound-insulating filter 72L, and the dynamic filter 74L correspond to the left channel of the left and right two channels, and the attenuator 66R, the high-pass filter 68R, the low-pass filter 70R, the sound-insulating filter 72R, and the dynamic filter 74R correspond to the right channel of the left and right two channels.

[0030] The attenuator 66L is a circuit that adjusts the level of the left channel sound signal of the two-channel sound signals to a level suitable for driving the speaker 40L, and the attenuator 66R is a circuit that adjusts the level of the right channel sound signal of the two-channel sound signals to a level suitable for driving the speaker 40R.

[0031] The high-pass filter 68L removes unnecessary high-frequency components from the electrical signal output from the attenuator 66L that are not suitable for output from the speaker 40L, and the high-pass filter 68R removes unnecessary high-frequency components from the electrical signal output from the attenuator 66R that are not suitable for output from the speaker 40R.

[0032] The low-pass filter 70L removes unnecessary low-frequency components from the electrical signal output from the high-pass filter 68L that are not suitable for output from the speaker 40L, and the low-pass filter 70R removes unnecessary low-frequency components from the electrical signal output from the high-pass filter 68R that are not suitable for output from the speaker 40R.

[0033] The sound insulation filters 72L and 72R are filters that simulate the sound insulation characteristics of the body of the vehicle. Specifically, the sound insulation filters 72L and 72R are filters that simulate the characteristics of the sound transmission system that runs from the engine through the body of the vehicle to the driver's ears.

[0034] Dynamic filter 74L and dynamic filter 74R are filters capable of controlling the frequency-gain characteristics. For example, in order to provide a powerful sound according to the engine speed, dynamic filter 74L and dynamic filter 74R are controlled so as to raise the gain of a frequency band around 400 Hz when the engine speed per unit time is around 3000 rpm, and dynamic filter 74L and dynamic filter 74R are controlled so as to raise the gain of a frequency band around 1 kHz when the engine speed per unit time is around 6000 rpm, with respect to the engine sound heard by the driver.

[0035] The left channel sound signal output from the filter 44 passes through an attenuator 66L, a high pass filter 68L, a low pass filter 70L, a sound insulation filter 72L, and a dynamic filter 74L in this order, and is output as the final left channel sound signal to the speaker 40L. The right channel sound signal output from the filter 44 passes through an attenuator 66R, a high pass filter 68R, a low pass filter 70R, a sound insulation filter 72R, and a dynamic filter 74R in this order, and is output as the final right channel sound signal to the speaker 40R.

[0036] An example of the operation of the sound field control device 10 will now be described.

[0037] For example, first, the control unit 30 identifies the driving state of the vehicle based on the depression amount of the accelerator pedal measured by the accelerator sensor 32 and the vehicle speed measured by the speed sensor 36. For example, the driving state of the vehicle is any one of a low-speed driving state, an acceleration start state, a transition state from an acceleration state to a high-speed driving state, and a high-speed driving state. The control unit 30 reads out sound image localization control parameters and the like corresponding to the identified driving state from the memory 38, and sets them in the multiple sound image localization processing units 56, 58, 60, 62, and the like.

[0038] For example, when the vehicle is traveling at a low speed, the control unit 30 reads out two sets of filter coefficient strings that have a low correlation coefficient with each other and cause the filter 44 to function as a decorrelation filter, and provides these to the filter 44. As a result, the sound images of the sounds reproduced from the speakers 40L and 40R are localized to occupy a wide area in the vehicle cabin, allowing the driver to hear the engine sound with a sense of spaciousness.

[0039] When the driver depresses the accelerator and the vehicle starts to accelerate, the control unit 30 reads out sound image localization control parameters for localizing the engine sound at one location and provides them to the sound image localization processors 56, 58, 60, and 62. When the vehicle starts to accelerate, the control unit 30 provides the filter 44 with a filter coefficient sequence that passes the two-channel sound signals without decorrelation, or two sets of filter coefficient sequences with a higher correlation coefficient than when the vehicle is in a low-speed driving state. This allows the driver to hear the engine sound with a sound image localized at one point in the vehicle cabin.

[0040] When the driving state of the vehicle is in a transition state from an acceleration state to a high-speed driving state, the control unit 30 reduces the correlation coefficient of the two sets of filter coefficient sequences to be applied to the filter 44. For example, a filter coefficient sequence to be applied to the filter 44 in association with the vehicle speed is stored in advance in the memory 38, and when the vehicle accelerates, the control unit 30 switches the filter coefficient sequence to be set in the filter 44 in accordance with the increasing speed, and applies a filter coefficient sequence according to the vehicle speed to the filter 44. As a result, the sound image of the engine sound heard by the driver becomes increasingly wider as the vehicle accelerates.

[0041] When the vehicle is traveling at high speed, the control unit 30 reads out a filter coefficient sequence that causes the filter 44 to function as a decorrelation filter, and applies the filter coefficient sequence to the filter 44. This enables the driver to hear the engine sound with a sense of spaciousness.

[0042] Other operation examples of the sound field control device 10 will be described below.

[0043] For example, when the vehicle's driving state is a steady driving state, the control unit 30 may give a sense of spaciousness to the engine sound reproduced from speakers 40L and 40R, and when downshifting on a slope or the like, may localize the sound image of the engine sound to a single point, and when the speed stabilizes and the vehicle returns to a steady driving state, the control unit 30 may return the engine sound reproduced from speakers 40L and 40R to a state in which the engine sound has a sense of spaciousness.

[0044] Also, for example, when the vehicle speed is stable, the control unit 30 may localize the sound images of the sound sources of the intake sound, the sound in the engine room, the exhaust sound, and the sound outside the vehicle at different positions in the vehicle cabin. Also, for example, the control unit 30 may localize only a specific sound source of the intake sound, the sound in the engine room, the exhaust sound, and the sound outside the vehicle in the front, and localize the sound sources other than the specific sound source in the rear. Specifically, for example, the control unit 30 may localize only the intake sound of the intake sound, the sound in the engine room, the exhaust sound, and the sound outside the vehicle in the front, and localize the sound sources other than the intake sound in the rear. In this case, the control unit 30 may change the position of the specific sound source according to the vehicle speed or the amount of depression of the accelerator pedal.

[0045] Also, for example, the control unit 30 may narrow down the sound source reproduced as the engine sound to one by adjusting the gains given to the multiple amplifiers 48, 50, 52, 54. This makes it easier to understand the sound image position compared to the case where sounds from multiple sound sources are reproduced. Note that, for example, the process of narrowing down the sound source to one may be performed when the vehicle is in a specific driving state, such as a state in which the vehicle is running quietly, or may be performed when the driver performs a specified operation.

[0046] The sound field control device 10 in the first embodiment has been described above.

[0047] The sound field control device 10 in the first embodiment includes a plurality of speakers 40L, 40R provided in a vehicle, a signal processing unit 28 that performs signal processing to impart a sound field effect to the sound reproduced from the plurality of speakers 40L, 40R in the process of generating multi-channel sound signals representing the engine sound and supplied to the plurality of speakers 40L, 40R, and a control unit 30 that controls the signal processing by the signal processing unit 28 based on the driving state of the vehicle.

[0048] According to this, the signal processing for imparting a sound field effect to the sound reproduced from the multiple speakers 40L, 40R can be controlled based on the driving state of the vehicle, so that the sound field inside the vehicle can be appropriately controlled. For example, when processing and reproducing engine sound, a sound field effect according to the driving state can be imparted to emphasize the presence of the engine. This makes it easier for the driver to feel the driving response from the reproduced engine sound, making it easier to drive comfortably.

[0049] Furthermore, in the sound field control device 10 in the first embodiment, the signal processing includes sound image localization processing for localizing the sound image of the sound reproduced from the multiple speakers 40L, 40R at a predetermined position, and the signal processing unit 28 has a sound image localization processing unit 56 (58, 60, 62) that performs the sound image localization processing.

[0050] According to this, the sound image of the sound reproduced from the multiple speakers 40L, 40R can be localized at a predetermined position, so that the sound field inside the vehicle can be more appropriately controlled.

[0051] Furthermore, in the sound field control device 10 in the first embodiment, the signal processing includes a filter process that controls the correlation coefficient of the sounds reproduced from the multiple speakers 40L, 40R, and the signal processing unit 28 has a filter 44 that performs the filter process.

[0052] According to this, the correlation coefficient of the sounds reproduced from the multiple speakers 40L, 40R can be controlled, making it easier to more appropriately control the sound field inside the vehicle.

[0053] (Second embodiment) FIG. 2 is a schematic diagram showing a sound field control device 10a according to the second embodiment.

[0054] As shown in FIG. 2, the sound field control device 10a includes a plurality of speakers 76L, 76R, 78L, and 78R provided in the vehicle 1, a signal processing unit 80, and a control unit .

[0055] The multiple speakers 76L, 76R, 78L, and 78R are provided in the front and rear parts of the vehicle 1. For example, the front part of the vehicle 1 is a part of the vehicle 1 that is forward of the rear end of the front seat 2 of the vehicle 1, and the rear part of the vehicle 1 is a part of the vehicle 1 that is rear of the rear end of the front seat 2 of the vehicle 1. In this embodiment, of the multiple speakers 76L, 76R, 78L, and 78R, the speaker 76L and the speaker 76R are provided in the front part of the vehicle 1, and the speaker 78L and the speaker 78R are provided in the rear part of the vehicle 1.

[0056] The multiple speakers 76L, 76R, 78L, and 78R are provided on the left and right sides of the front of the vehicle 1 and on the left and right sides of the rear of the vehicle 1. For example, the left of the front of the vehicle 1 is a portion of the front of the vehicle 1 that is to the left of the center of the vehicle 1 in the left-right direction, and the right of the front of the vehicle 1 is a portion of the front of the vehicle 1 that is to the right of the center of the vehicle 1 in the left-right direction. For example, the left of the rear of the vehicle 1 is a portion of the rear of the vehicle 1 that is to the left of the center of the vehicle 1 in the left-right direction, and the right of the rear of the vehicle 1 is a portion of the rear of the vehicle 1 that is to the right of the center of the vehicle 1 in the left-right direction. In this embodiment, of the multiple speakers 76L, 76R, 78L, and 78R, the speaker 76L is provided on the left of the front of the vehicle 1, the speaker 76R is provided on the right of the front of the vehicle 1, the speaker 78L is provided on the left of the rear of the vehicle 1, and the speaker 78R is provided on the right of the rear of the vehicle 1.

[0057] In the process of generating a multi-channel sound signal representing at least one of an engine sound, an engine exhaust sound, and a motor sound and being supplied to the multiple speakers 76L, 76R, 78L, and 78R, the signal processing unit 80 performs signal processing to impart a sound field effect to the sound reproduced from the multiple speakers 76L, 76R, 78L, and 78R. The signal processing includes a sound image localization process for localizing the sound image of the sound reproduced from the multiple speakers 76L, 76R, 78L, and 78R at a predetermined position. In this embodiment, the multi-channel sound signal is a four-channel sound signal. For example, the signal processing unit 80 generates a four-channel sound signal such that two of the four channels of sound signals represent the engine sound, and the other two of the four channels of sound signals represent the motor sound. In this embodiment, the engine sound includes a pseudo sound that simulates the engine sound, the engine exhaust sound includes a pseudo sound that simulates the engine exhaust sound, and the motor sound includes a pseudo sound that simulates the motor sound. The signal processing unit 80 has a sound image localization processing unit 84 that performs sound image localization processing. By referring to the above-mentioned description of the signal processing unit 28 and the sound image localization processing unit 56, a detailed description of the functional configurations of the signal processing unit 80 and the sound image localization processing unit 84 will be omitted.

[0058] The control unit 82 controls the signal processing by the signal processing unit 80 based on the driving state of the vehicle 1.

[0059] For example, the control unit 82 controls the sound image localization processing so that the engine sound arrives from the front of the vehicle 1 and the motor sound arrives from the rear of the vehicle 1. Specifically, for example, the control unit 82 controls the signal processing so that the engine sound is output from the multiple speakers 76L, 76R provided at the front of the vehicle 1, and controls the sound image localization processing so that the sound image of the output engine sound is localized at the front of the vehicle 1 (for example, near the windshield). In this way, the control unit 82 makes the engine sound arrive from the front of the vehicle 1. Also, for example, the control unit 82 controls the signal processing so that the motor sound is output from the multiple speakers 78L, 78R provided at the rear of the vehicle 1, and controls the sound image localization processing so that the sound image of the output motor sound is localized at the rear of the vehicle 1 (for example, near the rear glass). In this way, the control unit 82 makes the motor sound arrive from the rear of the vehicle 1.

[0060] Also, for example, the control unit 82 controls the output amount of the engine sound coming from the front of the vehicle 1 and the output amount of the motor sound coming from the rear of the vehicle 1 based on the driving state of the vehicle 1. Specifically, for example, the control unit 82 controls so that the output amount of the engine sound coming from the front of the vehicle 1 and the output amount of the motor sound coming from the rear of the vehicle 1 become larger as the acceleration of the vehicle 1 increases. In other words, for example, the control unit 82 controls so that the output amount of the engine sound coming from the front of the vehicle 1 and the output amount of the motor sound coming from the rear of the vehicle 1 become smaller as the acceleration of the vehicle 1 decreases. For example, the output amount is volume and / or sound pressure, etc.

[0061] Also, for example, the control unit 82 controls the sound image localization processing so that the motor sound arrives from the front of the vehicle 1 and the engine sound arrives from the rear of the vehicle 1. Specifically, for example, the control unit 82 controls the signal processing so that the motor sound is output from the multiple speakers 76L, 76R provided at the front of the vehicle 1, and controls the sound image localization processing so that the sound image of the outputted motor sound is localized at the front of the vehicle 1 (for example, near the windshield). In this way, the control unit 82 makes the motor sound arrive from the front of the vehicle 1. Also, for example, the control unit 82 controls the signal processing so that the engine sound is output from the multiple speakers 78L, 78R provided at the rear of the vehicle 1, and controls the sound image localization processing so that the sound image of the outputted engine sound is localized at the rear of the vehicle 1 (for example, near the rear glass). In this way, the control unit 82 makes the engine sound arrive from the rear of the vehicle 1.

[0062] Also, for example, the control unit 82 controls the sound image localization processing so that the engine sound arrives from the front of the vehicle 1 and the engine exhaust sound arrives from the rear of the vehicle 1. Specifically, for example, the control unit 82 controls the signal processing so that the engine sound is output from the multiple speakers 76L, 76R provided at the front of the vehicle 1, and controls the sound image localization processing so that the sound image of the output engine sound is localized at the front of the vehicle 1 (for example, near the windshield). In this way, the control unit 82 makes the engine sound arrive from the front of the vehicle 1. Also, for example, the control unit 82 controls the signal processing so that the engine exhaust sound is output from the multiple speakers 78L, 78R provided at the rear of the vehicle 1, and controls the sound image localization processing so that the sound image of the output engine exhaust sound is localized at the rear of the vehicle 1 (for example, near the rear glass). In this way, the control unit 82 makes the engine exhaust sound arrive from the rear of the vehicle 1.

[0063] Also, for example, the control unit 82 controls the sound image localization processing so that the motor sound arrives from near the wheels of the vehicle 1. Specifically, for example, the control unit 82 controls the signal processing so that the motor sound is output from multiple speakers 76L, 76R provided at the front of the vehicle 1, and controls the sound image localization processing so that the sound image of the output motor sound is localized at the feet of the front seat 2 of the vehicle 1. In this way, the control unit 82 makes the motor sound arrive from near the wheels of the vehicle 1.

[0064] Also, for example, the control unit 82 controls the distribution between the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1 in proportion to the distribution of driving force between the front and rear of the vehicle 1. That is, for example, the control unit 82 controls the output amount so that the distribution of driving force between the front and rear of the vehicle 1 and the distribution of the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1 are equal. Specifically, for example, when (driving force of the front wheels of the vehicle 1):(driving force of the rear wheels of the vehicle 1)=2:1, the control unit 82 controls the distribution between the output amount of sound coming from the front of the vehicle and the output amount of sound coming from the rear of the vehicle so that (output amount of sound coming from the front of the vehicle 1):(output amount of sound coming from the rear of the vehicle 1)=2:1.

[0065] Also, for example, the control unit 82 controls the distribution between the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1 when the vehicle 1 accelerates and decelerates. Specifically, for example, the control unit 82 controls the distribution between the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1 so that the output amount of sound coming from the front of the vehicle 1 is greater than the output amount of sound coming from the rear of the vehicle 1 when the vehicle 1 accelerates. Also, for example, the control unit 82 controls the distribution between the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1 so that the output amount of sound coming from the front of the vehicle 1 is smaller than the output amount of sound coming from the rear of the vehicle 1 when the vehicle 1 decelerates. In this way, for example, the control unit 82 controls the distribution between the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1 separately when the vehicle 1 accelerates and decelerates.

[0066] The sound field control device 10a in the second embodiment has been described above.

[0067] The sound field control device 10a in the second embodiment includes a plurality of speakers 76L, 76R, 78L, and 78R provided in a vehicle 1, a signal processing unit 80 that performs signal processing to impart a sound field effect to sounds reproduced from the plurality of speakers 76L, 76R, 78L, and 78R in the process of generating multi-channel sound signals representing at least one of engine sound, engine exhaust sound, and motor sound and that are supplied to the plurality of speakers 76L, 76R, 78L, and 78R, and a control unit 82 that controls the signal processing by the signal processing unit 80 based on the driving state of the vehicle 1.

[0068] This makes it possible to control signal processing that imparts a sound field effect to sounds reproduced from the multiple speakers 76L, 76R, 78L, and 78R based on the driving state of the vehicle 1, making it easier to appropriately control the sound field inside the vehicle 1.

[0069] In the sound field control device 10a in the second embodiment, the multiple speakers 76L, 76R, 78L, and 78R are provided at the front and rear of the vehicle 1.

[0070] This makes it possible to easily position the sound images of the sounds output from the multiple speakers 76L, 76R, 78L, and 78R at the front and rear of the vehicle 1, making it easier to control the sound field inside the vehicle 1 more appropriately.

[0071] In the sound field control device 10a in the second embodiment, the multiple speakers 76L, 76R, 78L, and 78R are provided on the left and right sides of the front of the vehicle 1 and on the left and right sides of the rear of the vehicle 1.

[0072] This makes it possible to easily position the sound images of the sounds output from the multiple speakers 76L, 76R, 78L, and 78R to the left and right sides of the front and rear of the vehicle 1, making it easier to appropriately control the sound field within the vehicle 1.

[0073] In the sound field control device 10a in the second embodiment, the control unit 82 controls the sound image localization process so that the engine sound arrives from the front of the vehicle 1 and the motor sound arrives from the rear of the vehicle 1.

[0074] According to this, since the engine sound can arrive from the front of the vehicle 1 and the motor sound can arrive from the rear of the vehicle 1, it becomes easier to control the sound field inside the vehicle 1 more appropriately.

[0075] In addition, in the sound field control device 10a in the second embodiment, the control unit 82 controls the output amount of engine sound coming from the front of the vehicle 1 and the output amount of motor sound coming from the rear of the vehicle 1 based on the driving state of the vehicle 1.

[0076] This makes it possible to control the output amount of engine sound coming from the front of vehicle 1 and the output amount of motor sound coming from the rear of vehicle 1 based on the driving state of vehicle 1, making it easier to control the sound field inside vehicle 1 more appropriately.

[0077] In the sound field control device 10a in the second embodiment, the control unit 82 controls the sound image localization process so that the motor sound arrives from the front of the vehicle 1 and the engine sound arrives from the rear of the vehicle 1.

[0078] According to this, the motor sound can be made to arrive from the front of the vehicle 1, and the engine sound can be made to arrive from the rear of the vehicle 1, making it easier to control the sound field inside the vehicle 1 more appropriately.

[0079] In the sound field control device 10a in the second embodiment, the control unit 82 controls the sound image localization process so that the engine sound arrives from the front of the vehicle 1 and the engine exhaust sound arrives from the rear of the vehicle 1.

[0080] According to this, the engine sound can arrive from the front of the vehicle 1, and the engine exhaust sound can arrive from the rear of the vehicle 1, making it easier to control the sound field inside the vehicle 1 more appropriately.

[0081] Moreover, in the sound field control device 10a in the second embodiment, the control unit 82 controls the sound image localization process so that the motor sound arrives from near the wheels of the vehicle 1.

[0082] According to this, since the motor sound can be made to arrive from near the wheels of the vehicle 1, it becomes easier to control the sound field inside the vehicle 1 more appropriately.

[0083] In addition, in the sound field control device 10a in the second embodiment, the control unit 82 controls the distribution of the output amount of sound arriving from the front of the vehicle 1 and the output amount of sound arriving from the rear of the vehicle 1 in proportion to the distribution of driving force between the front and rear of the vehicle 1.

[0084] This makes it possible to distribute the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1 in proportion to the distribution of driving force between the front and rear of the vehicle 1, making it easier to control the sound field inside the vehicle 1 more appropriately.

[0085] In addition, in the sound field control device 10a in the second embodiment, the control unit 82 controls the distribution of the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1 when the vehicle 1 is accelerating and decelerating.

[0086] According to this, when the vehicle 1 accelerates, it is possible to control the distribution between the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1, making it easier to more appropriately control the sound field inside the vehicle 1. Also, when the vehicle 1 decelerates, it is possible to control the distribution between the output amount of sound coming from the front of the vehicle 1 and the output amount of sound coming from the rear of the vehicle 1, making it easier to more appropriately control the sound field inside the vehicle 1.

[0087] (Other embodiments, etc.) Although the sound field control device according to one or more aspects has been described based on the embodiment, the present disclosure is not limited to this embodiment. As long as it does not deviate from the gist of the present disclosure, various modifications conceived by a person skilled in the art may also be included in the scope of the present disclosure.

[0088] In the above embodiment, the filter 44 functions as a decorrelation filter, but the present invention is not limited to this. For example, the filter 44 may not be provided, and the sound image localization processors 56, 58, 60, and 62 may be convolution calculators that function as decorrelation filters.

[0089] In the above embodiment, the driving state is specified by the current value of the output signal of the accelerator sensor 32, etc., but the present invention is not limited to this. For example, the driving state may be specified by the manner of time change of the output signal of the accelerator sensor 32, etc. Specifically, for example, the manner of time change of the output signal of one or more sensors within a certain period of time is defined as a motion state, and a plurality of motion states corresponding to the plurality of manners are defined. Then, a combination of the gain for each sound source, the sound image localization control parameter, and the filter coefficient sequence for adjusting the sense of sound spread is stored in advance in the memory 38 in association with each of the plurality of motion states. Then, when the vehicle is driven, pattern matching is performed between the manner of time change of the output signal of one or more sensors within a certain period of time in the past and the driving state stored in the memory 38, and the gain, etc. associated with the motion state that matches the manner is used for controlling the sound field effect. This makes it possible to impart a sound field effect that is more flexibly suited to the driving state to the engine sound.

[0090] In the above embodiment, the engine sound is collected, and the sound field effect is applied to the engine sound and the sound is reproduced from the multiple speakers 40L, 40R. However, the present invention is not limited to this. For example, the waveform data of the engine sound may be read from a memory in which the waveform data is stored in advance at a read speed corresponding to the engine speed, and a sound signal representing a pseudo engine sound may be reproduced and output from multiple speakers with a sound field effect applied to the sound signal according to the driving state. This provides the same effect as the sound field control device 10 in the above embodiment in a vehicle that does not have an engine and runs on a motor.

[0091] In the above embodiment, the engine sound is reproduced by two-channel speakers 40L and 40R, but the present invention is not limited to this. For example, the engine sound may be reproduced by a multi-channel speaker such as a four-channel or 5.1-channel speaker. [Industrial Applicability]

[0092] The present disclosure can be used in a sound field control device that controls a sound field in a vehicle cabin. [Explanation of symbols]

[0093] 10,10a Sound field control device 12,14,16,18 Mike 20,22,24,26,44 Filter 28,80 Signal processing section 30,82 Control section 32 Accelerator sensor 34 Shift sensor 36 Speed ​​Sensor 38 Memory 40L, 40R, 76L, 76R, 78L, 78R Speakers 42 Mixer 46 Processing section 48,50,52,54 Amplifier 56,58,60,62,84 Sound image localization processing section 64,66 signal line 66L, 66R Attenuator 68L, 68R High-pass filter 70L, 70R Low-pass filter 72L, 72R Soundproofing Filter 74L, 74R Dynamic Filter

Claims

1. A plurality of speakers provided in a vehicle; a signal processing unit that performs signal processing to impart a sound field effect to the sounds reproduced from the plurality of speakers in a process of generating a plurality of channel sound signals representing at least one of an engine sound, an engine exhaust sound, and a motor sound and being supplied to the plurality of speakers; a control unit that controls the signal processing by the signal processing unit based on a driving state of the vehicle, the signal processing includes a sound image localization process for localizing a sound image of the sound reproduced from the plurality of speakers at a predetermined position; The control unit controls the sound image localization process so that an engine sound arrives from the front of the vehicle and a motor sound arrives from the rear of the vehicle. Sound field control device.

2. A vehicle-mounted vehicle audio system comprising: a signal processing unit that performs signal processing to impart a sound field effect to the sounds reproduced from the plurality of speakers in a process of generating a plurality of channel sound signals representing at least one of an engine sound, an engine exhaust sound, and a motor sound and being supplied to the plurality of speakers; a control unit that controls the signal processing by the signal processing unit based on a driving state of the vehicle, the signal processing includes a sound image localization process for localizing a sound image of the sound reproduced from the plurality of speakers at a predetermined position; The control unit controls the sound image localization process so that a motor sound arrives from the front of the vehicle and an engine sound arrives from the rear of the vehicle. Sound field control device.

3. The plurality of speakers are provided at a front portion and a rear portion of the vehicle. The sound field control device according to claim 1 or 2.

4. The plurality of speakers are provided at the left and right sides of the front of the vehicle and at the left and right sides of the rear of the vehicle. The sound field control device according to claim 3 .

5. The control unit controls an output amount of engine sound coming from the front of the vehicle and an output amount of motor sound coming from the rear of the vehicle based on a driving state of the vehicle. The sound field control device according to claim 1 .

6. The control unit controls the distribution of the output amount of the sound coming from the front of the vehicle and the output amount of the sound coming from the rear of the vehicle in proportion to the distribution of the driving force between the front and rear of the vehicle. The sound field control device according to any one of claims 1 to 5.

7. The control unit controls a distribution between an output amount of a sound coming from the front of the vehicle and an output amount of a sound coming from the rear of the vehicle when the vehicle is accelerating and decelerating. The sound field control device according to any one of claims 1 to 6.

8. The signal processing includes a filter process for controlling a correlation coefficient of sounds reproduced from the plurality of speakers; The signal processing unit has a filter that performs the filtering process. The sound field control device according to any one of claims 1 to 7.

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