Acoustic signal control device and method

Abstract

The purpose of the present invention is to reduce a sense of incongruity when a driver rides and drives a mobile object by auditorily making up for the difference between the actual acceleration of the mobile object and the acceleration felt by the driver listening to an engine sound.　This acoustic signal control device comprises: a sound effect generation unit that generates a plurality of sound effects using a pseudo engine sound, which is an acoustic signal obtained by reproducing an engine sound generated by a mobile object or a simulator that simulates the movement of the mobile object; and a sound image position control unit that controls sound image positions, which are positions at which sound images of the plurality of sound effects are localized, on the basis of the acceleration of the mobile object or the simulator and an estimated value of auditory acceleration, which is the acceleration felt by an occupant of the mobile object or the simulator listening to the engine sound.

Description

[Technical Field]

[0001] The present disclosure relates to an audio signal control device and method. [Background technology]

[0002] 2. Description of the Related Art A vehicle interior sound field control device has been proposed that can generate realistic engine sounds that reflect the driving conditions in the vehicle interior of a moving object such as an automobile. As a prior art, for example, a device has been proposed that increases the sense of realism when a driver is driving a moving vehicle by adding an effect that increases the sense of spaciousness to a simulated engine sound (pseudo engine sound) (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-10810 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional technology described in Patent Document 1 has the following problems. For example, if there is a difference between the actual acceleration of a moving object and the acceleration that the driver perceives by listening to the engine sound, the driver will feel uncomfortable. Specifically, if the engine speed increases but the speed does not increase when the driver opens the accelerator, the driver will feel uncomfortable, such as "the acceleration is not linear, it is slow." This conventional technology cannot auditorily compensate for the difference between the actual acceleration of a moving object and the acceleration that the driver perceives by listening to the engine sound, and therefore cannot alleviate the discomfort the driver feels when driving a moving object.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to reduce the sense of discomfort felt by a driver when boarding and driving a moving body by auditorily compensating for the difference between the actual acceleration of the moving body and the acceleration that the driver perceives by listening to the engine sound. [Means for solving the problem]

[0006] The acoustic signal control device according to the present disclosure includes: a sound effect generating unit that generates a plurality of sound effects using a pseudo engine sound, which is an acoustic signal that reproduces an engine sound generated by a moving object or a simulator that simulates the operation of the moving object; a sound image position control unit that controls a sound image position, which is a position where sound images of the plurality of sound effects are localized, based on an acceleration of the moving body or the simulator and an estimated value of an audible acceleration, which is the acceleration experienced by an occupant of the moving body or the simulator by listening to the engine sound; It has.

[0007] The acoustic signal control method according to the present disclosure includes: a sound effect generation unit generates a plurality of sound effects using a pseudo engine sound, which is an acoustic signal that reproduces an engine sound generated by a moving object or a simulator that simulates the operation of the moving object; A sound image position control unit controls the sound image position, which is the position where the sound images of the multiple sound effects are located, based on the acceleration of the moving body or the simulator and an estimated value of the audible acceleration, which is the acceleration that the occupants of the moving body or the simulator experience by listening to the engine sound. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to reduce the sense of discomfort felt by a driver when driving a vehicle. [Brief explanation of the drawings]

[0009] [Figure 1]1 is a block diagram showing a configuration of an acoustic signal control device according to a first embodiment. [Figure 2] 2 is a diagram showing an example of a specific configuration of the acoustic signal control device according to the first embodiment. [Figure 3] 1 is a diagram illustrating a hardware configuration of an acoustic signal control device according to a first embodiment. [Figure 4] 4 is a flowchart showing the operation of the acoustic signal control device in the first embodiment. [Figure 5] FIG. 10 is a block diagram showing the configuration of an acoustic signal control device according to a second embodiment. [Figure 6] 10 is a flowchart showing the operation of the acoustic signal control device in the second embodiment. [Figure 7] FIG. 11 is a block diagram showing the configuration of an acoustic signal control device according to a third embodiment. [Figure 8] 11 is a flowchart showing the operation of the acoustic signal control device in the third embodiment. [Figure 9] FIG. 10 is a block diagram showing the configuration of an acoustic signal control device according to a fourth embodiment. [Figure 10] 10 is a flowchart showing the operation of the acoustic signal control device in the fourth embodiment. [Figure 11] FIG. 13 is a block diagram showing the configuration of an acoustic signal control device according to a fifth embodiment. [Figure 12] 13 is a flowchart showing the operation of the acoustic signal control device in the fifth embodiment. [Figure 13] FIG. 20 is a block diagram showing the configuration of an acoustic signal control device according to a sixth embodiment. [Figure 14] 13 is a flowchart showing the operation of the acoustic signal control device in the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described with reference to the drawings. The following embodiments are merely examples, and various modifications are possible within the scope of the present invention. In the description of the embodiments and the drawings, the same elements and corresponding elements are given the same reference numerals. The description of elements given the same reference numerals will be omitted or simplified as appropriate. In the following embodiments, "unit" may be read as "circuit," "step," "procedure," or "process" as appropriate.

[0011] Embodiment 1 <Configuration> The acoustic signal control device according to the first embodiment will be described with reference to Figures 1 to 4. Figure 1 is a block diagram showing the configuration of the acoustic signal control device 1 according to the first embodiment. 1, the sound signal control device 1 is made up of a sound effect generation unit 2 and a sound image position control unit 3. The sound effect generation unit 2 is made up of a sound signal generation unit 4 and a sound signal control unit 5. The sound image position control unit 3 is made up of an auditory acceleration estimation unit 6, a sound image position calculation unit 7, and a delay time calculation unit 8.

[0012] The mobile body 20 is a mobile body that can be moved by driving or operating a driver 24 who is an occupant on board. The mobile body 20 may also have a passenger 25 other than the driver 24 on board as an occupant. The mobile body 20 is, for example, an automobile, a motorcycle, a truck, a train, a ship, an airplane, or the like. The mobile body 20 is equipped with an engine 21, a steering mechanism, driven devices such as wheels, power resources such as batteries and fuel, and the like, all of which are not shown. The engine 21 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine, or an electric motor. The engine 21 may be a hybrid configuration that combines an internal combustion engine and an electric motor.

[0013] The mobile object 20 may be a driving simulator that simulates the operation of the mobile object 20. The driving simulator simulates the operation of the mobile object 20, such as the moving or driving state of the mobile object 20 and the operation of the engine. The driving simulator includes a control device (not shown) such as a computer for simulating the operation of the mobile object 20. The driving simulator may include an audio device such as a speaker (not shown) and a display device such as a display (not shown) to allow the driver 24 to experience the moving state of the mobile object 20. The driving simulator may include a housing in which the driver 24 can ride, similar to an actual mobile object. The control device of the driving simulator can generate a simulated engine sound that simulates the operation of the engine 21. Similar to an actual mobile object, the control device of the driving simulator can change the volume, sound quality, frequency characteristics, etc. of the simulated engine sound in accordance with the driving operation of the driver 24. The simulated engine sound may be output so as to be heard by the driver 24 using an audio device (e.g., a speaker) installed in place of the engine 21. The simulated engine sound may be output using one or more of the speakers 23a to 23d.

[0014] Hereinafter, unless otherwise specified, the moving body 20 will be described as including a driving simulator for the moving body 20. Furthermore, unless otherwise specified, the engine sound generated by the engine 21 of the moving body 20 will be described as including a simulated engine sound generated by the driving simulator for the moving body 20.

[0015] The sound effect generation unit 2 generates a pseudo engine sound 102, which is an acoustic signal that reproduces the engine sound generated by the moving object 20, based on the engine sound information 101. The sound effect generation unit 2 then generates a plurality of sound effects 103 using a plurality of delay times 107 (described later) and the pseudo engine sound 102. The plurality of sound effects 103 represent all or some of the sound effects 103a to 103d. Note that when there is no need to explain the sound effects 103a to 103d individually, they will be abbreviated as the plurality of sound effects 103.

[0016] The sound image position control unit 3 controls the sound image position 106, which indicates the position where the sound image 26 generated by the multiple sound effects 103 is located, based on the engine sound information 101 and the speed information 104. A sound image is an audible sound source that is generated when the same sound is applied to the left and right ears of a person from multiple directions. The driver 24 or passenger 25 perceives the sound image 26 at the position indicated by the sound image position 106.

[0017] The acoustic signal generator 4 uses various pieces of information indicated by the engine sound information 101 to generate a pseudo engine sound 102, which is an acoustic signal that reproduces the engine sound generated by the moving object 20. For example, the pseudo engine sound 102 is a digital signal with a sampling frequency of 16 kHz, an amplitude resolution of 16 bits, and separated by a predetermined frame length (10 msec), and is generated at a predetermined frame period. For simplicity of the following explanation, the frame period is assumed to be 10 msec, and the pseudo engine sound 102 is synchronized with the frame length at a time length that is the same as the frame length, but the frame period is not limited to 10 msec. For example, the frame period may be 20 msec, which is a time length different from the frame length (10 msec). In this case, the pseudo engine sound 102 is generated as a digital signal for two consecutive frames of the same content.

[0018] The engine sound information 101 is information about the engine 21 provided in the moving body 20, such as engine speed information of an internal combustion engine or an electric motor, engine model information, etc. For example, the engine sound information 101 may be acquired at a predetermined frame period in synchronization with the frame period of the pseudo engine sound 102, but the frame period of the engine sound information 101 is not limited to this. The period for acquiring the engine sound information 101 does not have to be synchronized with the frame period of the pseudo engine sound 102. The engine sound information 101 may also be information about a simulated engine sound generated by a driving simulator of the moving body 20.

[0019] The engine rotation speed information may be, for example, the rotation speed of the output shaft of the engine 21 per predetermined time, the number of explosions in each cylinder per predetermined time, etc. For example, the engine rotation speed information may be acquired via an ECU (Electronic Control Unit) 22 that controls the engine 21. The engine rotation speed information may be estimated from an electrical signal of an ignition coil or vibration of the engine 21. Alternatively, the engine rotation speed information may be a signal obtained from the rotation speed of a transmission, drive shaft, or drive sprocket connected to the engine 21. The engine rotation speed information may be acquired from a control device that controls the driving simulator.

[0020] The engine type information is, for example, information about the type of internal combustion engine when engine 21 is an internal combustion engine. For example, the information about the type of internal combustion engine includes the number of cylinders, the number of rotors, the cylinder arrangement (in-line, V-type, horizontally opposed, etc.), the ignition method (spark ignition, compression ignition, etc.), and whether or not a supercharger is used. Furthermore, the engine type information is, for example, information about the type of electric motor when engine 21 is an electric motor. For example, the information about the type of electric motor includes the number of electric motors and the output of the electric motors. Note that the information about the type of electric motor may include information about the type of the internal combustion engine to be simulated, and information about the shape or type of the mobile object to be simulated (for example, a sports car, an SUV (sport utility vehicle), a motorcycle, a bus, a truck, a train, a ship, an aircraft, etc.).

[0021] The acoustic signal generation unit 4 may generate the pseudo engine sound 102 based on information other than the engine sound information 101. For example, the acoustic signal generation unit 4 may use a microphone to record engine sounds in the cabin or engine room of the moving body 20 in real time and generate the recorded engine sound as the pseudo engine sound 102. Alternatively, the acoustic signal generation unit 4 may generate the pseudo engine sound 102 by processing or modifying a pre-recorded engine sound. Furthermore, the acoustic signal generation unit 4 may generate the pseudo engine sound 102 by detecting vibrations of the engine 21 using, for example, a vibration pickup and estimating the engine sound from the detected vibrations of the engine 21. Note that the pseudo engine sound 102 is preferably generated based on the shape of the moving body 20; however, the shape of the moving body 20 and the type of moving body that generates the pseudo engine sound 102 may be different. For example, if the moving body 20 is an automobile, the pseudo engine sound 102 may be an aircraft engine sound (e.g., a gas turbine engine sound). Alternatively, the artificial engine sound 102 may be generated from a signal sound such as a sine wave or a square wave.

[0022] The sound signal control unit 5 generates a plurality of sound effects 103 by delaying the pseudo engine sound 102 according to a plurality of delay times 107, which will be described later. More specifically, the sound signal control unit 5 uses filters 9a to 9d to delay the pseudo engine sound 102 according to delay times 107a to 107d corresponding to each filter, thereby generating sound effects 103a to 103d, respectively. For example, the frame length of each of the sound effects 103a to 103d is 10 msec, the same as that of the pseudo engine sound 102. The filters 9a to 9d are filters that change the phase of a signal, and are, for example, all-pass filters, phase shifters, delay filters, etc.

[0023] The sound effects 103a to 103d are sent to the driver 24 in the vehicle 20 using the speakers 23a to 23d, respectively. If a passenger 25 other than the driver 24 is in the vehicle 20, the generated sound effects 103a to 103d may also be sent to the passenger 25.

[0024] Here, a mechanism for imparting a sense of movement to the driver 24 in the moving object 20 by "auditory vection," which is a feature of the acoustic signal control device of this embodiment, will be described.

[0025] In general, the acceleration that the driver 24 feels when listening to the engine sound is a psychologically perceived acceleration that is recalled based on the past experiences of the driver 24. Specifically, when the volume of the engine sound increases or the frequency of the engine sound increases as the engine speed increases, the driver 24 feels as if the mobile object 20 is accelerating.

[0026] Additionally, there is a known phenomenon based on human perceptual psychology called visually induced self-motion sensation (vection). Vection is a phenomenon in which, when a visual stimulus moving in a uniform direction is presented across a wide field of view, the observer experiences an illusory sensation of their own body moving in the opposite direction to that movement. As a specific example, if an observer is on a stopped train and sees a train moving on the opposite platform, the observer will have the illusion that their own train is moving. Vection is generally a visual phenomenon, but it is known that moving sound can also cause vection in the auditory sense. This vection in the auditory sense is called "auditory vection." In this embodiment, the sound image position control unit 3 induces "auditory vection" in the driver 24 by moving the localization position of the pseudo engine sound 102 (i.e., sound image 26). As a result, the driver 24 aboard the moving object 20 feels that the moving object 20 is accelerating.

[0027] In this application, the acceleration that the driver 24 feels when listening to the engine sound is distinguished by calling the psychologically perceived acceleration that is recalled based on the driver's 24's past experiences "auditory acceleration" and the perceived acceleration that is induced by the movement of the pseudo engine sound 102 (i.e., auditory vection) "auditory vection acceleration." Note that, because the engine sound is also heard by passengers 25 other than the driver 24, passengers 25 other than the driver 24 may be included in the definitions of auditory acceleration and auditory vection acceleration.

[0028] Both auditory vection acceleration and auditory acceleration are accelerations that the driver 24 experiences by listening to the engine sound, but the nature of auditory vection acceleration and the nature of auditory acceleration are different. Auditory vection acceleration is perceived only by the "movement" of the sound image 26. Therefore, auditory vection acceleration does not depend on the sound quality of the sound effects that make up the sound image. Furthermore, auditory vection acceleration gives the driver 24 the illusion that he or she is moving. Therefore, like physical acceleration (acceleration G), auditory vection acceleration has properties similar to the acceleration of actual movement. Therefore, auditory vection acceleration can auditorily compensate (create) the difference with the actual acceleration of the moving object 20. In other words, auditory vection acceleration can reduce the difference between the actual acceleration of the moving object 20 and auditory acceleration (i.e., the psychological acceleration experienced due to an increase in engine sound volume, an increase in engine speed, etc.). At this time, by controlling the auditory vection acceleration according to the difference between the auditory acceleration and the actual acceleration of the moving body 20, it is possible to prevent excessive auditory vection acceleration. By controlling the acceleration felt by the driver 24 based on the auditory vection acceleration, the sense of discomfort felt by the driver 24 is alleviated. As a result, the driver 24's complaints, such as "acceleration is not linear, it's slow," are resolved. Furthermore, the driver 24 can drive smoothly without further opening the accelerator.

[0029] Furthermore, the position of the sound image 26 can be freely controlled by a psychoacoustic effect known as the "precedence effect." The "precedence effect" is a phenomenon in which, for example, when the same sound is transmitted from two different directions, if one of the sounds is delayed, it is perceived as a single sound coming from the direction of the sound that reaches the ear first. Due to the "precedence effect," the position of the sound image 26 changes depending on the arrival time difference between sounds from multiple different directions. The acoustic signal control device of this embodiment can freely control the position of the sound image 26 by controlling the delay times of the multiple sound effects. In other words, various changes in the position of the sound image 26 can be perceived by the driver 24.

[0030] The audible acceleration estimation unit 6 estimates the audible acceleration using the engine sound information 101, and outputs audible acceleration information 105 indicating information on the estimated value of the audible acceleration. The audible acceleration information 105 may include information on the estimated value of the audible acceleration of a passenger 25 other than the driver 24. The auditory acceleration information 105 can be calculated by a regression equation based on linear regression analysis using data previously obtained from a sensory evaluation experiment, for example. Equation (1) is an example of the regression equation. Using equation (1), the auditory acceleration A' can be estimated from the amount of change ΔR in the engine speed of the engine 21.

[0031]

number

[0032] The sound image position calculation unit 7 calculates a sound image position 106 that indicates the position of the sound image 26 perceived by the driver 24, which is a sound image generated by the multiple sound effects 103, based on the audible acceleration information 105 and the speed information 104. More specifically, if there is a difference between the audible acceleration A' that the driver 24 feels from the engine sound and the actual acceleration A of the moving object 20, the sound image position calculation unit 7 calculates the sound image position 106 so as to move the sound image 26.

[0033] The speed information 104 is information that indicates the actual moving speed and moving direction of the moving body 20. For example, the speed information 104 can be obtained from a vehicle speed sensor provided in the moving body 20, information from the steering angle of the steering wheel, a global positioning system (GPS), an inertial measurement unit (IMU), the ECU 22 of the moving body 20, etc. For example, the speed information 104 may be acquired at predetermined frame intervals, similar to the frame period of the pseudo engine sound 102, but it does not have to be synchronized with the frame period of the pseudo engine sound 102. The actual acceleration A of the moving body 20 can be calculated from the derivative of the velocity of the moving body 20 or the difference per predetermined time using the velocity information 104. Alternatively, the actual acceleration A of the moving body 20 may be calculated directly from an acceleration sensor provided in the moving body 20.

[0034] The delay time calculation unit 8 calculates a plurality of delay times 107 according to a sound image position 106 indicating the position where the sound image 26 is localized. The plurality of delay times 107 are all or part of the delay times 107a to 107d. The method of calculating the delay times 107a to 107d will be described later. Note that when there is no need to explain the delay times 107a to 107d individually, they will be abbreviated as the plurality of delay times 107.

[0035] 2 is an example showing a specific configuration of the acoustic signal control device 1 in the first embodiment. In the example of FIG. 2, the moving body 20 is an automobile. A driver 24 and a passenger 25 are on board the moving body 20. Speakers 23a to 23d are arranged to surround the driver 24 and the passenger 25. Speakers 23a and 23b are arranged in front of the driver 24 and the passenger 25. Speakers 23c and 23d are arranged behind the driver 24 and the passenger 25. D / A 27 is a digital-to-analog converter that converts the plurality of sound effects 103, which are digital signals, into analog signals. Amplification device 28 is, for example, an audio amplifier, and amplifies the plurality of sound effects 103 output from D / A 27. The amplified plurality of sound effects 103 are output from speakers 23a-23d, respectively. Driver 24 then perceives sound image 26 generated by sound effects 103a-103d.

[0036] When there is a difference between the auditory acceleration A' felt by the driver 24 and the actual acceleration A of the moving object 20, the sound image position calculation unit 7 moves the sound image position so as to induce "auditory vection." As shown in FIG. 2, for example, when the moving object 20 accelerates, the sound image 26 is moved from in front of the driver 24 to behind (arrow "R" in FIG. 2). Also, for example, when the moving object 20 decelerates, the sound image 26 is moved from behind the driver 24 to in front (arrow "F" in FIG. 2). By moving the sound image 26 in this way, it is possible to induce "auditory vection" in the driver 24, and therefore it is possible to auditorily compensate for the difference between the actual acceleration of the moving object and the acceleration felt by the driver by listening to the engine sound.

[0037] Here, the number of the current frame is t, and the auditory acceleration of the current frame and the actual acceleration of the moving object 20 in the current frame are A'(t) and A(t), respectively. If the acceleration at which the sound image 26 moves (i.e., the auditory vection acceleration) is defined as a(t) = A'(t) - A(t) and the direction of movement of the sound image 26 is limited to only the direction of travel of the moving object 20, then the distance that the sound image 26 moves per frame (i.e., the amount of displacement of the sound image position) Δx(t) can be expressed, for example, by equation (2).

[0038]

number

[0039] In equation (2), Δx(t), which is the difference between the sound image position (x(t)) of the sound image 26 in the current frame and the sound image position (x(t-1)) of the previous frame, becomes larger as the difference between the audible acceleration A' and the actual acceleration A of the moving object 20 becomes larger. In other words, the greater the difference between the two accelerations, the greater the distance the sound image 26 moves. Note that the example of equation (2) is a case where the difference between the audible acceleration A' and the actual acceleration of the moving object 20 is compensated for, but this is not limiting. For example, a stronger sense of acceleration may be created by making the acceleration a(t) of the movement of the sound image position 106 larger than the actual acceleration A of the moving object 20.

[0040] The delay time calculation unit 8 calculates a plurality of delay times 107 according to a sound image position 106 (x(t)) indicating the position where the sound image 26 is localized. As an example of delay time calculation, as shown in FIG. 2, a line segment CL indicating the midpoint between the driver 24 and the passenger 25 is defined, and a case where the sound image 26 is moved back and forth on this line segment CL will be described. The midpoint indicates that the distance from an arbitrary point on the line segment CL to the driver 25 is equal to the distance from the same arbitrary point to the passenger 26. Note that the acoustic signal transmission characteristics (acoustic space characteristics) within the vehicle cabin are affected by reflection or diffraction by seats, window glass, etc., but for simplicity of explanation, the vehicle cabin will be described as a free sound field unaffected by reflection or diffraction.

[0041] The effects of reflection or diffraction within the vehicle cabin can be reduced, for example, by using a filter having the inverse characteristics of the acoustic spatial characteristics within the vehicle cabin. For example, the acoustic spatial characteristics within the vehicle cabin can be obtained from an impulse response. Specifically, a reference signal such as a time stretched pulse (TSP) is sent from each speaker and the reference signal is acquired using a microphone installed at the position of the driver 25, thereby obtaining an impulse response. Then, filter coefficients having the inverse characteristics of the acoustic spatial characteristics can be calculated from the impulse response. By adding the filter coefficients with the inverse characteristics thus obtained to the filter coefficients of filters 9a to 9d, sound effects 103a to 103d can be corrected to signals in which the effects of reflection or diffraction are canceled out.

[0042] First, we will explain the case where sound image 26a is localized in the center between the two front speakers using only speakers 23a and 23b. In this case, the distance from speaker 23a to sound image 26a is equal to the distance from speaker 23b to sound image 26a, so delay time 107a and delay time 107b should be set to the same value. By doing so, the arrival time of sound effect 103a sent from speaker 23a to sound image 26a is the same as the arrival time of sound effect 103b sent from speaker 23b to sound image 26a. Therefore, sound image 26a generated by sound effect 103a and sound effect 103b is localized in the center between the two front speakers.

[0043] Next, we will explain the case where sound image 26b is localized in the center between the two rear speakers using only speakers 23c and 23d. In this case, as with the case of the two front speakers, delay times 107c and 107d should be set to the same value. By doing so, the arrival time of sound effect 103c sent from speaker 23c to sound image 26b is the same as the arrival time of sound effect 103d sent from speaker 23d to sound image 26b. Therefore, sound image 26b generated by sound effect 103c and sound effect 103d is localized in the center between the two rear speakers.

[0044] Next, we will explain the case where sound image 26 is moved back and forth along line segment CL using four speakers, 23a to 23d. If delay times 107a to 107d are all set to the same value, the sound effects 103a to 103d emitted from speakers 23a to 23d will all take the same time to reach sound image 26. Therefore, sound image 26 will be localized at the center of the four speakers. Note that sound image 26 can be considered to be a sound image generated by sound images 26a and 26b. Therefore, if a certain time difference is provided between the set of delay times 107a and 107b and the set of delay times 107c and 107d, a "precedence effect" will occur between sound image 26a and sound image 26b. As a result, the position of sound image 26 changes along line segment CL depending on the time difference. To position sound image 26 in front of the center position of the four speakers, the arrival time of the sound effects output from the front speakers should be made earlier than the arrival time of the sound effects output from the rear speakers. That is, the delay time of the pair of delay times 107a and 107b should be made shorter than the delay time of the pair of delay times 107c and 107d. To position sound image 26 behind the center position of the four speakers, the arrival time of the sound effects output from the rear speakers should be made earlier than the arrival time of the sound effects output from the front speakers. That is, the delay time of the pair of delay times 107c and 107d should be made shorter than the delay time of the pair of delay times 107a and 107b. That is, by controlling the delay time between the front and rear speakers, it is possible to move sound image 26 forward or backward.

[0045] The above describes an example in which sound image 26 is moved in the front-to-back direction. Using a similar principle, sound image 26 can also be moved in the left-to-right direction. Specifically, a certain time difference is provided between the delay time of the right speaker (i.e., the set of delay times 107a and 107c) and the delay time of the left speaker (i.e., the set of delay times 107b and 107d). Therefore, by controlling the delay times of multiple sound effects, it is possible to freely control the position of sound image 26.

[0046] The arrival time difference between each of the plurality of sound effects 103 is determined according to the sound image position (x(t)) of the current frame indicated by the sound image position 106. The delay time calculation unit 8 calculates the delay time of each of the sound effects 103a to 103d according to the determined arrival time difference, and outputs the delay times 107a to 107d, respectively.

[0047] As illustrated in FIG. 2, the speakers 23a to 23d are preferably installed so as to surround the driver 24 or the passenger 25, but this is not limitative. Because the interior shape of the vehicle 20 differs depending on the type of vehicle, the installation positions of the speakers 23a to 23d may be changed as appropriate. The height of the installation positions of the speakers 23a to 23d is preferably based on, for example, the ear height of the driver 24 or the passenger 25, but this is not limitative. For example, the speakers 23a to 23d may be installed on the ceiling of the vehicle 20 or near the feet of the driver 24. The number of speakers is not limited to four and may be, for example, five or more. Note that if the number of speakers is two or more, the sound image position 26 can be moved, and for example, a configuration with two speakers, speaker 23a and speaker 23c, is also possible.

[0048] 2, the sense of acceleration (or deceleration) of the moving object 20 is audibly enhanced by moving the sound image 26 in front of or behind the driver 24, but this is not limiting. For example, the sound image 26 may be moved from the right side to the left side (or from the left side to the right) of the driver 24 according to the speed information 104. By moving the sound image 26 left and right, it is possible to create a sense of turning of the moving object 20 for the driver 24, thereby increasing the driver's satisfaction during driving.

[0049] 2, speakers 23a to 23d are arranged horizontally, but the arrangement of the speakers is not limited to horizontal. For example, the speakers may be arranged above and below driver 24, such as by placing speaker 23b above the driver's head and speaker 23d at the driver's feet. By arranging the speakers above and below driver 24, sound image 26 can also be moved in the vertical direction of driver 24. By moving sound image 26 in the vertical direction of driver 24, it is possible to reduce the sense of discomfort felt when driving a mobile object capable of three-dimensional movement (such as an aircraft, drone, or submarine).

[0050] <Hardware> Each component of the acoustic signal control device 1 shown in Fig. 1 can be realized, for example, by a computer, which is an information processing device having a built-in processor. Fig. 3 is a diagram showing the hardware configuration of the acoustic signal control device 1 in embodiment 1. In Fig. 3, the acoustic signal control device 1 is made up of a processor 30, a memory 31, a storage device 32, an interface 33, and a signal path 34.

[0051] The computer incorporating the processor 30 is, for example, a microcomputer for embedding in a device, a SoC (System on Chip), etc. Alternatively, it may be a portable computer such as a smartphone or a tablet computer.

[0052] The processor 30 controls the entire acoustic signal control device 1. For example, the processor 30 is a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), etc. The processor 30 may be a single processor or multiple processors. Furthermore, the acoustic signal control device 1 may have a processing circuit such as an ASIC (Application Specific Integrated Circuit) in addition to a computer. The processing circuit may be a single circuit or a composite circuit.

[0053] The memory 31 is a main storage device of the acoustic signal control device 1. For example, the memory 31 holds data necessary for the operation of the processor 30. For example, the memory 31 is a RAM (Random Access Memory).

[0054] The storage device 32 is an auxiliary storage device for the acoustic signal control device 1. For example, the storage device 32 stores initial value data, programs, error logs, etc. required for the operation of the acoustic signal control device 1. For example, the storage device 32 is a ROM (Read Only Memory), an HDD (Hard Disk Drive), or an SSD (Solid State Drive).

[0055] The interface 33 is an input / output interface for transmitting and receiving data to and from external devices connected to the acoustic signal control device 1. For example, the interface 33 is a network interface controller (NIC). For example, the external devices are the D / A 27 and the ECU 22 in the example of FIG. 3. The interface 33 inputs engine sound information 101 and speed information 104 output from the ECU 22 to the processor 30. The interface 33 outputs a plurality of sound effects 103 output from the processor 30 to the D / A 27. The interface 33 is also a device that inputs information necessary for controlling the acoustic signal control device 1 and commands to execute control processing for the acoustic signal control device 1.

[0056] The signal path 34 is a transmission path (bus) for transmitting and receiving data between the components of the acoustic signal control device 1 shown in FIG.

[0057] The processor 30 reads the acoustic signal control program stored in the storage device 32 into the memory 31 via the signal path 34. The processor 30 then executes the program to realize each process of the acoustic signal control method. The storage device 32 holds programs and data for realizing the acoustic signal control method of the first embodiment. The acoustic signal control program may be supplied from outside the acoustic signal control device 1 via the interface 33. The acoustic signal control program may also be provided by a computer-readable non-volatile storage medium (for example, a CD (Compact Disc), a DVD (Digital Versatile Disc), a flash memory, etc.). That is, the acoustic signal control program may be provided as a program product, for example.

[0058] The acoustic signal control device 1 is mounted on the mobile object 20, but is not limited to this. For example, if the mobile object 20 is a driving simulator, it may be configured by a computer or the like located at a different location from the mobile object 20. In this case, various information about the mobile object 20 may be input to the acoustic signal control device 1 on the computer by data transmission via a communication network connected to the interface 33, for example. Furthermore, the multiple sound effects 103 generated by the acoustic signal control device 1 on the computer may be sent to the D / A 27 of the mobile object 20 via the communication network, for example. The communication network may be, for example, a wired or wireless network, such as a dedicated line such as a LAN (Local Area Network), or the Internet.

[0059] <Operation> Next, a description will be given of the operation of the acoustic signal control device 1 in Embodiment 1. Fig. 4 is a flowchart showing the operation of the acoustic signal control device 1 in Embodiment 1.

[0060] In step ST1, the acoustic signal generating unit 4 generates the artificial engine sound 102 using the engine sound information 101 (step ST1).

[0061] In step ST2, the audible acceleration estimation unit 6 estimates the audible acceleration using the engine sound information 101, and outputs audible acceleration information 105 indicating information on the estimated value of the audible acceleration (step ST2).

[0062] In step ST3, the sound image position calculation unit 7 calculates the sound image position 106, which indicates the position of the sound image 26 generated by the multiple sound effects 103 and perceived by the driver 24, based on the audible acceleration information 105 and the speed information 104 (step ST3).

[0063] In step ST4, the delay time calculation unit 8 calculates a plurality of delay times 107 according to the position indicated by the sound image position 106. Specifically, the delay times of the sound effects 103a to 103d output by the filters 9a to 9d are calculated, and output as delay times 107a to 107d, respectively (step ST4).

[0064] In step ST5, the sound signal control unit 5 generates a plurality of sound effects 103 by delaying the pseudo engine sound 102 according to a plurality of delay times 107 (step ST5).

[0065] The process of step ST1 only needs to be performed before the process of step ST5, and therefore the process of step ST1 may be performed after any of the processes of steps ST2 to ST4.

[0066] As described above, the acoustic signal control device of this embodiment generates multiple sound effects using pseudo engine sounds that reproduce the engine sounds produced by a moving body based on engine sound information and multiple delay times, and controls the sound image position, which indicates the position where the sound image generated by the multiple sound effects is located, by controlling the delay times of each of the multiple sound effects based on the engine sound information and speed information. Therefore, the acoustic signal control device of this embodiment can auditorily compensate for the difference between the actual acceleration of the moving body and the acceleration that the driver experiences by listening to the engine sound by moving the position where the sound image of the pseudo engine sound is located, thereby reducing the sense of discomfort felt by the driver when riding in and driving the moving body.

[0067] Embodiment 2 In the above-described first embodiment, the sound image position is controlled by delaying each of the multiple sound effects, but the method for controlling the sound image position is not limited to delay. For example, it is possible to control the sound image position by changing the volume of each of the multiple sound effects. This will be described as a second embodiment.

[0068] Fig. 5 is a block diagram showing the configuration of an acoustic signal control device 1 in embodiment 2. New components compared to Fig. 1 are a gain calculation unit 10 and gain control units 11a to 11d. The other components and operations are the same as those in Fig. 1, and therefore description thereof will be omitted.

[0069] The gain calculation unit 10 calculates gains indicating the volume of the plurality of sound effects 103 according to the sound image position 106 indicating the position where the sound image 26 is localized. The obtained gains are output as a plurality of gains 108. The plurality of gains 108 are all or some of the gains 108a to 108d. Note that when there is no need to explain the gains 108a to 108d individually, they will be abbreviated as the plurality of gains 108.

[0070] In order for the gain calculation unit 10 to change the position of the sound image 26 by controlling the volumes of the multiple sound effects 103, a method generally known as "panning" can be used. Specifically, in the example of FIG. 2, to localize the sound image 26 forward of the center position of the four speakers, the volume of the sound effects output from the front speakers is made larger than the volume of the sound effects output from the rear speakers. That is, the gain (i.e., volume) of the pair of gains 108a and 108b is made larger than the gain (i.e., volume) of the pair of gains 108c and 108d. Also, to localize the sound image 26 rearward of the center position of the four speakers, the volume of the sound effects output from the rear speakers is made larger than the volume of the sound effects output from the front speakers. That is, the gain of the pair of gains 108c and 108d is made larger than the gain of the pair of gains 108a and 108b. Therefore, by controlling the volume of each of the plurality of sound effects 103, the position of the sound image 26 can be freely controlled.

[0071] The sound signal control unit 5 generates a plurality of sound effects 103 by controlling the volume of the pseudo engine sound 102 in accordance with a plurality of gains 108. More specifically, the sound signal control unit 5 uses gain control units 11a to 11d to control the volume of the pseudo engine sound 102 in accordance with gains 108a to 108d, thereby generating sound effects 103a to 103d, respectively. For example, the gain control units 11a to 11d are devices that control the amplitude of digital signals, such as amplifiers or attenuators. Note that the gain control units 11a to 11d may have filters that have inverse characteristics of the acoustic space characteristics, similar to the filters 9a to 9d described in the first embodiment.

[0072] Fig. 6 is a flowchart showing the operation of the acoustic signal control device 1 in embodiment 2. The processes from step ST1 to step ST3 are the same as those shown in Fig. 1 in embodiment 1, and therefore a description thereof will be omitted.

[0073] In step ST4A, gain calculation unit 10 calculates multiple gains 108 indicating the volume of multiple sound effects 103 according to the position indicated by sound image position 106. Specifically, gains of sound effects 103a to 103d output by filters 9a to 9d are calculated, respectively, and output as gains 108a to 108d, respectively (step ST4A).

[0074] In step ST5A, the sound signal control unit 5 generates a plurality of sound effects 103 by controlling the volume of the pseudo engine sound 102 in accordance with a plurality of gains 108 (step ST5A).

[0075] As described above, the acoustic signal control device of this embodiment generates multiple sound effects using pseudo engine sounds that reproduce the engine sounds produced by a moving body, based on engine sound information and gains that indicate the volume of the multiple sound effects, and controls the sound image position, which indicates the position where the sound image generated by the multiple sound effects is located, by controlling the gains of each of the multiple sound effects based on the engine sound information and speed information. Therefore, the acoustic signal control device of this embodiment can auditorily compensate for the difference between the actual acceleration of the moving body and the acceleration that the driver experiences by listening to the engine sound by moving the position where the sound image of the pseudo engine sound is located, thereby reducing the sense of discomfort felt by the driver when riding in and driving the moving body.

[0076] Embodiment 3 In the above-described first embodiment, the sound image position is controlled by delaying each of the multiple sound effects, but the method for controlling the sound image position is not limited to delay. For example, it is possible to control the sound image position by adding reverberation to each of the multiple sound effects. This will be described as a third embodiment.

[0077] Fig. 7 is a block diagram showing the configuration of an acoustic signal control device 1 according to embodiment 3. New components compared to Fig. 1 are a reverberation time calculation unit 12 and reverberation control units 13a to 13d. The other components and operations are the same as those in Fig. 1, and therefore will not be described again.

[0078] The reverberation time calculation unit 12 calculates reverberation times indicating the duration of reverberation of the plurality of sound effects 103 according to the sound image position 106 indicating the position where the sound image 26 is located. The obtained reverberation times are output as a plurality of reverberation times 109. The plurality of reverberation times 109 are all or part of the reverberation times 109a to 109d. When it is not necessary to explain the reverberation times 109a to 109d individually, they are abbreviated as the plurality of reverberation times 109.

[0079] Generally, a sound source with a long reverberation time is perceived as having been affected by reflection or diffraction to a large extent, and therefore is perceived as having come from a distance. On the other hand, a sound source with a short reverberation time is perceived as having been affected by reflection or diffraction to a small extent, and therefore is perceived as having been received from a nearby location. Applying this principle, the position of the sound image can be controlled by controlling the reverberation times of the multiple sound effects 103. Specifically, in the example of FIG. 2, to localize sound image 26 in front of the center position of the four speakers, the reverberation time of the sound effects output from the front speakers is set shorter than the reverberation time of the sound effects output from the rear speakers. In other words, the reverberation time of the pair of reverberation times 109a and 109b should be set shorter than the reverberation time of the pair of reverberation times 109c and 109d. To position sound image 26 behind the center of the four speakers, the reverberation time of the sound effects emitted from the rear speakers should be set shorter than the reverberation time of the sound effects emitted from the front speakers. That is, the reverberation time of the pair of reverberation times 109c and 109d should be set shorter than the reverberation time of the pair of reverberation times 109a and 109b. Therefore, by controlling the reverberation times of the multiple sound effects 103, it is possible to freely control the position of sound image 26.

[0080] The sound signal control unit 5 generates a plurality of sound effects 103 by adding reverberation to the pseudo engine sound 102 in accordance with a plurality of reverberation times 109. More specifically, the sound signal control unit 5 uses the reverberation control units 13a to 13d to control the reverberation time of the pseudo engine sound 102 in accordance with the reverberation times 109a to 109d (in other words, by adding reverberation), thereby generating the sound effects 103a to 103d, respectively. For example, the reverberation control units 13a to 13d are filters that generate reverberation, such as comb filters. Note that the reverberation control units 13a to 13d may have filters having the inverse characteristics of the acoustic space characteristics, similar to the filters 9a to 9d described in the first embodiment.

[0081] Fig. 8 is a flowchart showing the operation of the acoustic signal control device 1 in embodiment 3. The processes from step ST1 to step ST3 are the same as those shown in Fig. 1 in embodiment 1, and therefore a description thereof will be omitted.

[0082] In step ST4B, the reverberation time calculation unit 12 calculates a plurality of reverberation times 109 indicating the duration of reverberation of the plurality of sound effects 103, according to the position indicated by the sound image position 106. Specifically, the reverberation times of the sound effects 103a to 103d output by the filters 9a to 9d are calculated, respectively, and output as reverberation times 109a to 109d, respectively (step ST4B).

[0083] In step ST5B, the sound signal control unit 5 generates a plurality of sound effects 103 by adding reverberation to the pseudo engine sound 102 according to a plurality of reverberation times 109 (step ST5B).

[0084] As described above, the acoustic signal control device of this embodiment generates multiple sound effects using pseudo engine sounds that reproduce the engine sounds generated by a moving body, and controls the reverberation times of the multiple sound effects based on engine sound information and speed information, thereby controlling the sound image position, which indicates the location where the sound image generated by the multiple sound effects is located. Therefore, the acoustic signal control device of this embodiment can auditorily compensate for the difference between the actual acceleration of the moving body and the acceleration that the driver experiences by listening to the engine sound by moving the position where the sound image of the pseudo engine sound is located, thereby reducing the sense of discomfort felt by the driver when riding in and driving the moving body.

[0085] Embodiment 4 The configuration of the first embodiment can also be combined with the configuration of the second embodiment. Specifically, it is possible to delay a plurality of sound effects and then control the volume of the delayed sound effects. This will be described as the fourth embodiment.

[0086] Fig. 9 is a block diagram showing the configuration of an acoustic signal control device 1 according to embodiment 4. Compared to Fig. 1, new components include a gain calculation unit 10 and gain control units 11a to 11d. The other components and operations are the same as those in Fig. 1, and therefore will not be described again.

[0087] The gain calculation unit 10 calculates gains indicating the volume of a plurality of sound effects 103 according to a sound image position 106 indicating the position where the sound image 26 is localized. The obtained gains are output as a plurality of gains 108.

[0088] The sound signal control unit 5 controls the volume of each of the plurality of sound effects 103 in accordance with the plurality of gains 108. More specifically, the sound signal control unit 5 uses gain control units 11a to 11d to control the volume of each of the sound effects 103a to 103d in accordance with the gains 108a to 108d.

[0089] Humans perceive the position of a sound image using slight differences in sound information generated at the left and right ears depending on the position of the sound source, i.e., the object that generates the sound waves. In this case, the interaural time difference (ITD) predominates in the low frequency range, while the interaural level difference (ILD) predominates in the high frequency range. Therefore, depending on the frequency characteristics of the pseudo engine sound 102 (i.e., the multiple sound effects 103), it may be difficult to control the sound image position 106 by controlling only the delay time or the volume. Furthermore, if the difference in delay time between each of the multiple sound effects 103 is large, specifically, if the difference in delay time exceeds approximately 0.04 seconds, the multiple sound effects will no longer be localized as a single sound image. As a result, the multiple sound effects will be perceived as separate echoes, and the precedence effect will no longer occur. Therefore, by combining delay time control and gain control in controlling the sound image position 106 using multiple sound effects 103, the weaknesses of both control methods can be compensated for, and the sound image position 106 can be controlled with high precision.

[0090] As a method of combining control of the delay time and gain of the multiple sound effects 103, for example, the sound image position 106 can be controlled by controlling the delay time for the low-frequency components of the multiple sound effects 103 and controlling the gain for the high-frequency components of the multiple sound effects 103. More specifically, the delay time calculation unit 8 calculates the delay time for the low-frequency components of the pseudo engine sound 102 that are below a predetermined threshold (e.g., frequency components below 2000 Hz), and the gain calculation unit 10 calculates the gain for the high-frequency components of the pseudo engine sound 102 that are equal to or above the predetermined threshold (e.g., frequency components equal to or above 2000 Hz). Note that the predetermined threshold is not limited to 2000 Hz and may be another value. For example, the predetermined threshold may be changed as appropriate depending on the frequency characteristics of the pseudo engine sound 102, the type of moving object, etc. Furthermore, the method of calculating the delay time and gain does not depend on a predetermined threshold value, but rather, for example, the control of sound image position 106 by the delay time and gain may be proportionally distributed according to the frequency of pseudo engine sound 102. For example, the ratio between the control of the delay time and the control of the gain may be such that the ratio of control by gain increases as the frequency of pseudo engine sound 102 (i.e., the plurality of sound effects 103) increases.

[0091] As another method for combining the control of the delay times and gains of the plurality of sound effects 103, for example, when the delay times of the plurality of sound effects 103 exceed a predetermined threshold (e.g., 0.04 seconds), a volume difference corresponding to the delay time can be generated among the plurality of sound effects 103 to control the sound image position. More specifically, when the sound image position calculation unit 7 calculates the sound image position 106 and the result exceeds a threshold indicating a predetermined delay time difference, the gain calculation unit 10, instead of the delay time calculation unit 8, calculates the plurality of gains 108 so that the sound image 26 is localized at the position indicated by the sound image position 106. Note that the threshold indicating the predetermined delay time difference is not limited to 0.04 seconds and may be another value. For example, the threshold indicating the predetermined delay time difference may be changed as appropriate depending on the type of vehicle, the size of the vehicle interior, etc. Furthermore, the delay time and gain may be calculated not by a threshold value indicating a predetermined delay time, but by proportionally dividing the delay time and the gain, for example. For example, the ratio of gain control to delay time control may be increased as the delay time becomes longer.

[0092] Fig. 10 is a flowchart showing the operation of the acoustic signal control device 1 in embodiment 4. The processes from step ST1 to step ST4 are the same as those shown in Fig. 1 in embodiment 1, and therefore a description thereof will be omitted.

[0093] In step ST4A, gain calculation unit 10 calculates multiple gains 108 indicating the volume of multiple sound effects 103 according to the position indicated by sound image position 106. Specifically, gains of sound effects 103a to 103d output by filters 9a to 9d are calculated, respectively, and output as gains 108a to 108d, respectively (step ST4A).

[0094] In step ST5, the sound signal control unit 5 generates a plurality of sound effects 103 by delaying the pseudo engine sound 102 according to a plurality of delay times 107 (step ST5).

[0095] In step ST6A, the sound signal control unit 5 controls the volumes of the sound effects 103 according to the gains 108. More specifically, the sound signal control unit 5 uses the gain control units 11a to 11d to control the volumes of the sound effects 103a to 103d according to the gains 108a to 108d, respectively (step ST6A).

[0096] As described above, the acoustic signal control device of this embodiment generates a plurality of sound effects using pseudo engine sounds that reproduce the engine sounds generated by a moving body, and controls the delay times of the plurality of sound effects based on engine sound information and speed information, and also controls the gains of the plurality of sound effects, thereby controlling the sound image position, which indicates the position where the sound image generated by the plurality of sound effects is located. Therefore, the acoustic signal control device of this embodiment can auditorily compensate for the difference between the actual acceleration of the moving body and the acceleration that the driver experiences by listening to the engine sound by moving the position where the sound image of the pseudo engine sound is located, thereby reducing the sense of discomfort felt by the driver when riding in and driving the moving body.

[0097] Furthermore, the acoustic signal control device of this embodiment combines delay time control and volume control in controlling the sound image position using multiple sound effects, thereby making up for the weaknesses of both control methods and enabling accurate control of the sound image position.

[0098] Embodiment 5 The configuration of the first embodiment can also be combined with the configuration of the third embodiment. Specifically, it is possible to delay a plurality of sound effects and further add reverberation to the plurality of sound effects. This will be described as the fifth embodiment.

[0099] Fig. 11 is a block diagram showing the configuration of an acoustic signal control device 1 according to embodiment 5. Compared to Fig. 1, new components include a reverberation time calculation unit 12 and reverberation control units 13a to 13d. The other components and operations are the same as those in Fig. 1, and therefore will not be described again.

[0100] The reverberation time calculation unit 12 calculates the reverberation time indicating the duration of reverberation of the plurality of sound effects 103 according to the sound image position 106 indicating the position where the sound image 26 is located. The obtained reverberation time is output as a plurality of reverberation times 109.

[0101] The sound signal control unit 5 adds reverberation to each of the sound effects 103 in accordance with each of the reverberation times 109. More specifically, the sound signal control unit 5 controls the reverberation time (adds reverberation) of each of the sound effects 103a to 103d in accordance with the reverberation times 109a to 109d using the reverberation control units 13a to 13d.

[0102] Fig. 12 is a flowchart showing the operation of the acoustic signal control device 1 in embodiment 5. The processes from step ST1 to step ST4 are the same as those shown in Fig. 1 in embodiment 1, and therefore the explanation will be omitted.

[0103] In step ST4B, the reverberation time calculation unit 12 calculates a plurality of reverberation times 109 indicating the duration of reverberation of the plurality of sound effects 103, according to the position indicated by the sound image position 106. Specifically, the reverberation times of the sound effects 103a to 103d output by the filters 9a to 9d are calculated, respectively, and output as reverberation times 109a to 109d, respectively (step ST4B).

[0104] In step ST5, the sound signal control unit 5 generates a plurality of sound effects 103 by delaying the pseudo engine sound 102 according to a plurality of delay times 107 (step ST5).

[0105] In step ST6B, the sound signal control unit 5 controls the reverberation times of the sound effects 103 in accordance with the reverberation times 109. More specifically, the sound signal control unit 5 uses the reverberation control units 13a to 13d to control the reverberation times of the sound effects 103a to 103d in accordance with the reverberation times 109a to 109d, respectively (step ST6B).

[0106] As described above, the acoustic signal control device of this embodiment generates a plurality of sound effects using pseudo engine sounds that reproduce the engine sounds generated by a moving body, and controls the delay times of the plurality of sound effects based on engine sound information and speed information, and also controls the reverberation times of the plurality of sound effects, thereby controlling the sound image position, which indicates the location where the sound image generated by the plurality of sound effects is located. Therefore, the acoustic signal control device of this embodiment can auditorily compensate for the difference between the actual acceleration of the moving body and the acceleration that the driver experiences by listening to the engine sound by moving the position where the sound image of the pseudo engine sound is located, thereby reducing the sense of discomfort felt by the driver when riding in and driving the moving body.

[0107] Furthermore, the acoustic signal control device of this embodiment combines delay time control and reverberation time control in controlling the sound image position using multiple sound effects, thereby making it possible to compensate for the weaknesses of control using delay time and to control the sound image position with high precision.

[0108] Embodiment 6 Furthermore, the configuration of the first embodiment can be combined with the configuration of the second embodiment and the configuration of the third embodiment. Specifically, it is possible to delay a plurality of sound effects, control the volume of the plurality of sound effects, and add reverberation to the plurality of sound effects. This will be described as the sixth embodiment.

[0109] Fig. 13 is a block diagram showing the configuration of an acoustic signal control device 1 according to embodiment 6. Compared to Fig. 1, new components include a gain calculation unit 10, gain control units 11a to 11d, reverberation time calculation unit 12, and reverberation control units 13a to 13d. The other components and operations are the same as those in Fig. 1, and therefore will not be described again.

[0110] The gain calculation unit 10 calculates gains indicating the volume of a plurality of sound effects 103 according to a sound image position 106 indicating the position where the sound image 26 is localized. The obtained gains are output as a plurality of gains 108.

[0111] The reverberation time calculation unit 12 calculates the reverberation time indicating the duration of reverberation of the plurality of sound effects 103 according to the sound image position 106 indicating the position where the sound image 26 is located. The obtained reverberation time is output as a plurality of reverberation times 109.

[0112] The sound signal control unit 5 controls the volume of each of the plurality of sound effects 103 in accordance with the plurality of gains 108. More specifically, the sound signal control unit 5 uses gain control units 11a to 11d to control the volume of each of the sound effects 103a to 103d in accordance with the gains 108a to 108d.

[0113] Furthermore, the sound signal control unit 5 imparts reverberation to each of the sound effects 103 in accordance with each of the reverberation times 109. More specifically, the sound signal control unit 5 controls the reverberation time of each of the sound effects 103a to 103d (i.e., imparts reverberation) in accordance with the reverberation times 109a to 109d using the reverberation control units 13a to 13d.

[0114] Fig. 14 is a flowchart showing the operation of the acoustic signal control device 1 in embodiment 6. The processes from step ST1 to step ST4 are the same as those shown in Fig. 1 in embodiment 1, and therefore the explanation will be omitted.

[0115] In step ST4A, gain calculation unit 10 calculates multiple gains 108 indicating the volume of multiple sound effects 103 according to the position indicated by sound image position 106. Specifically, gains of sound effects 103a to 103d output by filters 9a to 9d are calculated, respectively, and output as gains 108a to 108d, respectively (step ST4A).

[0116] In step ST4B, the reverberation time calculation unit 12 calculates a plurality of reverberation times 109 indicating the duration of reverberation of the plurality of sound effects 103, according to the position indicated by the sound image position 106. Specifically, the reverberation times of the sound effects 103a to 103d output by the filters 9a to 9d are calculated, respectively, and output as reverberation times 109a to 109d, respectively (step ST4B).

[0117] In step ST5, the sound signal control unit 5 generates a plurality of sound effects 103 by delaying the pseudo engine sound 102 according to a plurality of delay times 107 (step ST5).

[0118] In step ST6A, the sound signal control unit 5 controls the volumes of the sound effects 103 according to the gains 108. More specifically, the sound signal control unit 5 uses the gain control units 11a to 11d to control the volumes of the sound effects 103a to 103d according to the gains 108a to 108d, respectively (step ST6A).

[0119] In step ST6B, the sound signal control unit 5 controls the reverberation times of the sound effects 103 in accordance with the reverberation times 109. More specifically, the sound signal control unit 5 uses the reverberation control units 13a to 13d to control the reverberation times of the sound effects 103a to 103d in accordance with the reverberation times 109a to 109d, respectively (step ST6B).

[0120] As described above, the acoustic signal control device of this embodiment generates a plurality of sound effects using pseudo engine sounds that reproduce the engine sounds generated by a moving body, and controls the delay times, volume levels, and reverberation times of the plurality of sound effects based on engine sound information and speed information, thereby controlling the sound image position, which indicates the location where the sound image generated by the plurality of sound effects is located. Therefore, the acoustic signal control device of this embodiment can auditorily compensate for the difference between the actual acceleration of the moving body and the acceleration that the driver experiences by listening to the engine sound by moving the position where the sound image of the pseudo engine sound is located, thereby reducing the sense of discomfort felt by the driver when riding in and driving the moving body.

[0121] Furthermore, the acoustic signal control device of this embodiment combines control based on delay time, control based on volume, and control based on reverberation time in controlling the sound image position using multiple sound effects, so it is possible to compensate for the weaknesses of each control method and control the sound image position with high precision.

[0122] In the sixth embodiment, a case has been described in which control based on delay time, control of volume, and control of reverberation time are performed. The control based on delay time may be omitted from the acoustic signal control device of the sixth embodiment, and the same effects as those described above can be achieved.

[0123] The features of the above-described embodiments can be combined with each other as appropriate. [Industrial Applicability]

[0124] The acoustic signal control device according to the present disclosure is applicable to various moving bodies or moving body simulators, such as automobiles, trains, ships, and aircraft, etc. In particular, the acoustic signal control device according to the present disclosure is suitable for use in moving bodies driven by a driver, and in driving simulators for moving bodies that simulate the driving state of a driver. [Explanation of symbols]

[0125] 1 Acoustic signal control device, 2 Sound effect generation unit, 3 Sound image position control unit, 4 Acoustic signal generation unit, 5 Acoustic signal control unit, 6 Auditory acceleration estimation unit, 7 Sound image position calculation unit, 8 Delay time calculation unit, 9a, 9b, 9c, 9d Filters, 10 Gain calculation unit, 11a, 11b, 11c, 11d Gain control unit, 12 reverberation time calculation unit, 13a, 13b, 13c, 13d reverberation control units, 20 Vehicle, 21 Engine, 22 ECU, 23a, 23b, 23c, 23d Speaker, 24 Driver, 25 Passenger, 26, 26a, 26b Sound image, 27 D / A, 28 Amplification equipment, 30 processor, 31 memory, 32 storage device, 33 interface, 34 signal path.

Claims

1. a sound effect generating unit that generates a plurality of sound effects using a pseudo engine sound, which is an acoustic signal that reproduces an engine sound generated by a moving object or a simulator that simulates the operation of the moving object; a sound image position control unit that controls a sound image position, which is a position where sound images of the plurality of sound effects are localized, based on an acceleration of the moving body or the simulator and an estimated value of an audible acceleration, which is the acceleration experienced by an occupant of the moving body or the simulator by listening to the engine sound; An acoustic signal control device having:

2. Further comprising a delay time calculation unit, the delay time calculation unit calculates delay times of the plurality of sound effects based on the acceleration of the moving object or the simulator and the estimated value of the auditory acceleration; The sound image position control unit controls the sound image position in accordance with the delay time.

2. The acoustic signal control device according to claim 1, wherein:

3. Further comprising a gain calculation unit, the gain calculation unit calculates gains indicating volumes of the plurality of sound effects based on the acceleration of the moving object or the simulator and the estimated value of the auditory acceleration; The sound image position control unit controls the sound image position in accordance with the gain.

2. The acoustic signal control device according to claim 1, wherein:

4. Further comprising a reverberation time calculation unit, the reverberation time calculation unit calculates the reverberation times of the plurality of sound effects based on the acceleration of the moving object or the simulator and the estimated value of the auditory acceleration, The sound image position control unit controls the sound image position in accordance with the reverberation time.

2. The acoustic signal control device according to claim 1, wherein:

5. Further comprising a delay time calculation unit and a gain calculation unit, The delay time calculation unit calculates delay times of the plurality of sound effects based on the acceleration of the moving object or the simulator and the estimated value of the auditory acceleration, and the gain calculation unit calculates gains indicating volumes of the plurality of sound effects based on the acceleration of the moving object or the simulator and the estimated value of the auditory acceleration; The sound image position control unit controls the sound image position in accordance with the delay time and the gain.

2. The acoustic signal control device according to claim 1, wherein:

6. the sound image position control unit controls delay times of low-frequency components of the plurality of sound effects, The sound image position is controlled by controlling a gain indicating the volume of a high-frequency component of the plurality of sound effects.

6. The acoustic signal control device according to claim 5,

7. the sound image position control unit controls the sound image position in accordance with the delay time when the delay time is less than a predetermined threshold value; When the delay time is equal to or greater than the threshold value, the sound image position is controlled in accordance with the gain.

6. The acoustic signal control device according to claim 5,

8. the sound image position control unit controls the position of the sound image by increasing a proportion of control by the gain as the frequencies of the plurality of sound effects become higher.

6. The acoustic signal control device according to claim 5,

9. the sound image position control unit controls the position of the sound image by increasing a proportion of control by the gain as the delay times of the plurality of sound effects become longer.

6. The acoustic signal control device according to claim 5,

10. a sound effect generation unit generates a plurality of sound effects using a pseudo engine sound, which is an acoustic signal that reproduces an engine sound generated by a moving object or a simulator that simulates the operation of the moving object; a sound image position control unit that controls sound image positions, which are positions where sound images of the plurality of sound effects are localized, based on an acceleration of the moving body or the simulator and an estimated value of audible acceleration, which is the acceleration experienced by an occupant of the moving body or the simulator by listening to the engine sound; Acoustic signal control method.

Images