Sound signal processing device, sound signal processing method and program

Abstract

A sound signal processing device (100) is provided with: an acquisition unit (110) that acquires a sound signal (AS1); a first signal processing unit (120a) that generates, on the basis of the audio signal (AS1), a first high-range signal including a high-range component of a frequency band higher than a first frequency that is higher than the audible range of a person; and an addition unit (130) that adds the first high-range signal to the sound signal (AS1) and generates an expanded sound signal having an expanded high range. A first signal processing unit (120a, i) performs first signal processing including first clipping processing for clipping at a first amplitude on a sound signal (AS1), and (ii) performs first high-pass filtering processing for passing a frequency band higher than a first frequency on a sound signal (AS3) after the first clipping processing.

Description

Technical Field

[0001] The present disclosure relates to a sound signal processing device, a sound signal processing method, and a program. Background Art

[0002] Patent Document 1 discloses a technique for extending the high-frequency range of an audio signal.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2000 / 070769 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The present disclosure provides a sound signal processing device and the like that can easily expand the high-frequency range of a sound signal that does not have a 1 / f characteristic, such as a sound signal of natural sound, so as to reduce the sense of discomfort to people.

[0008] Means used to solve problems

[0009] A sound signal processing device according to a technical solution of the present disclosure comprises: an acquisition unit for acquiring a sound signal; a first signal processing unit for generating, based on the sound signal, a first high-range signal including high-range components of a frequency band higher than a first frequency, wherein the first frequency is higher than the audible range of a human; and an addition unit for adding the first high-range signal to the sound signal to generate an extended sound signal with an extended high-range, wherein the first signal processing unit (i) performs a first signal processing including a first clipping processing of clipping with a first amplitude on the sound signal, and (ii) performs a first high-pass filtering processing on the sound signal after the first clipping processing to pass a frequency band higher than the first frequency, thereby generating the first high-range signal.

[0010] In addition, a sound signal processing method according to a technical solution of the present disclosure obtains a sound signal, generates a first high-range signal including high-range components of a frequency band higher than a first frequency based on the sound signal, wherein the first frequency is higher than the audible range of a human, adds the first high-range signal to the sound signal, and generates an extended sound signal with an extended high-range. In the generation of the first high-range signal, the sound signal is subjected to a first signal processing including a first clipping processing of clipping with a first amplitude, and the sound signal after the first clipping processing is subjected to a first high-pass filtering processing that allows a frequency band higher than the first frequency to pass, thereby generating the first high-range signal.

[0011] In addition, these global or specific technical solutions can also be implemented by devices, integrated circuits, computer programs or non-transitory recording media such as computer-readable CD-ROMs, or by any combination of devices, integrated circuits, computer programs and non-transitory recording media.

[0012] Effects of the Invention

[0013] The sound signal processing device and the like of the present disclosure can easily expand the high-frequency range of a sound signal that does not have a 1 / f characteristic, such as a sound signal of natural sound, so as to reduce the sense of discomfort to people. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a block diagram showing an example of the configuration of a sound signal processing system according to an embodiment.

[0015] Figure 2 This is a diagram showing an example of the structure of the first signal processing unit according to the embodiment.

[0016] Figure 3 This is a diagram showing an example of the waveform of the audio signal before and after each process for explaining each process performed by the first signal processing unit according to the embodiment.

[0017] Figure 4 This is a diagram showing an example of the structure of the second signal processing unit related to the embodiment.

[0018] Figure 5 This is a diagram showing an example of the waveform of the audio signal before and after each process for explaining each process performed by the second signal processing unit according to the embodiment.

[0019] Figure 6 This is a flowchart showing an example of sound signal processing by the sound signal processing device according to the embodiment.

[0020] Figure 7 This is a flowchart showing an example of a process of generating a first high-range signal among N high-range signals according to the embodiment.

[0021] Figure 8 1 is a flowchart showing an example of an operation of generating a second high-range signal among N high-range signals according to the embodiment. DETAILED DESCRIPTION

[0022] (Understanding that is the basis of the present disclosure)

[0023] In the technology described in Patent Document 1, since filtering processing based on a 1 / f characteristic filter is performed as a premise, it does not consider expanding the high-frequency range of sound signals such as natural sounds that do not have a 1 / f characteristic. In other words, the conventional technology has the following problem: it is difficult to expand the high-frequency range of sound signals such as natural sounds that do not have a 1 / f characteristic so as to reduce the sense of discomfort.

[0024] The inventors of the present application have conducted special research to expand the high-frequency range of sound signals that do not have a 1 / f characteristic, such as sound signals such as natural sounds, so as to reduce the sense of discomfort to people, and have discovered the following sound signal processing device, sound signal processing method, and program.

[0025] The sound signal processing device of the first technical solution related to the present disclosure comprises: an acquisition unit, which acquires a sound signal; a first signal processing unit, which generates a first high-range signal including high-range components of a frequency band higher than a first frequency based on the sound signal, wherein the first frequency is higher than the audible range of a human; and an addition unit, which adds the first high-range signal to the sound signal to generate an extended sound signal with an extended high-range, wherein the first signal processing unit (i) performs a first signal processing including a first clipping processing of clipping with a first amplitude on the sound signal, and (ii) performs a first high-pass filtering processing on the sound signal after the first clipping processing to pass a frequency band higher than the first frequency, thereby generating the first high-range signal.

[0026] Thus, by performing the first clipping process of clipping the sound signal after the first amplification process with the first amplitude, a sound signal containing more high-frequency components (high harmonics) based on the original sound signal can be generated. In addition, since the sound signal after the first clipping process is subjected to the first high-pass filter process, a first high-frequency range signal with a large sound pressure in the high frequency range can be mainly generated, and by adding the first high-frequency range signal to the original sound signal, an extended sound signal in which the high frequency range of the original sound signal is extended can be generated. Thus, the high frequency range of a sound signal that does not have a 1 / f characteristic, such as a natural sound, can be easily extended so that the awkward feeling is reduced.

[0027] The sound signal processing device according to the second technical solution of the present disclosure is the sound signal processing device according to the first technical solution, wherein the first signal processing includes a first amplification process of amplifying the sound signal with a first gain, and the first clipping process performed on the sound signal after the first amplification process.

[0028] Thus, by the amplification process, the slope of the waveform of the original sound signal in the range of the sound pressure based on the first amplitude can be made steeper than before the amplification process, so the angle of the curved shape of the waveform of the sound signal after the clipping process can be made close to 90 degrees. Therefore, a sound signal containing more high-frequency components (for example, high-frequency components that are higher in frequency band than the original sound signal and in the inaudible range) can be generated.

[0029] The sound signal processing device related to the third technical solution of the present disclosure is a sound signal processing device related to the first technical solution or the second technical solution, wherein the first signal processing unit further performs a first attenuation processing to attenuate the sound signal after the first clipping processing with a second gain; and the first high-range signal is the sound signal after further performing the first attenuation processing.

[0030] Therefore, the amplitude of the first clipped audio signal containing more high-frequency components based on the original audio signal can be adjusted. Thus, the first high-frequency signal with appropriately adjusted amplitude can be generated, and the high-frequency range of the original audio signal can be appropriately expanded.

[0031] The sound signal processing device related to the fourth technical solution of the present disclosure is a sound signal processing device related to the first technical solution or the second technical solution, wherein the first signal processing unit further performs a first equalization processing to amplify or attenuate a specific frequency band of the sound signal after the first high-pass filtering processing; and the first high-range signal is the sound signal after further performing the first equalization processing.

[0032] Therefore, the frequency characteristic of the sound signal after the first high-pass filter processing can be adjusted. Thus, the first high-frequency signal with appropriately adjusted amplitude can be generated, and the high-frequency range of the original sound signal can be appropriately expanded.

[0033] The sound signal processing device related to the fifth technical solution of the present disclosure is a sound signal processing device related to the first technical solution or the second technical solution, wherein the first signal processing unit further performs a first attenuation processing for attenuating the sound signal after the first clipping processing with a second gain; performs a first equalization processing for amplifying or attenuating a specific frequency band of the sound signal after the first attenuation processing; and the first high-range signal is the sound signal after further performing the first equalization processing.

[0034] Therefore, the amplitude and frequency characteristics of the sound signal after the first high-pass filter processing can be adjusted. Thus, the first high-frequency signal with appropriately adjusted amplitude can be generated, and the high frequency range of the original sound signal can be appropriately expanded.

[0035] The sound signal processing device of the sixth technical solution of the present disclosure is a sound signal processing device related to any one of the technical solutions of the first to fifth technical solutions, and further comprises a second signal processing unit, which generates a second high-range signal different from the first high-range signal based on the sound signal, the second signal processing unit (i) performs a second signal processing including an offset processing of offsetting a predetermined sound pressure amount on the sound signal, (ii) performs a second clipping processing of clipping the sound signal after the second signal processing with a second amplitude, and (iii) performs a second high-pass filtering processing of passing a frequency band higher than a second frequency on the sound signal after the second clipping processing, thereby generating the second high-range signal, wherein the second frequency is higher than the audible range; the adding unit adds the first high-range signal and the second high-range signal to the sound signal to generate the extended sound signal.

[0036] Thus, by performing the second clipping process of clipping the sound signal after the offset process and the second amplification process with the second amplitude, a sound signal containing more high-frequency components based on the original sound signal can be generated. When the sound signal after the first clipping process is clipped without the offset process, it contains more odd-numbered frequency components, and the sound signal after the second clipping process contains more even-numbered frequency components because it is clipped after the offset process. Therefore, in this case, the frequency characteristics of the first high-range signal and the second high-range signal can be made different, and the high-range of the original sound signal can be expanded more effectively.

[0037] A sound signal processing device according to a seventh technical solution of the present disclosure is the sound signal processing device according to the sixth technical solution, wherein the second signal processing includes the offset processing and a second amplification processing of amplifying the sound signal after the offset processing with a third gain.

[0038] Thus, by the amplification process, the slope of the waveform of the sound signal after the offset process in the range of the sound pressure based on the second amplitude can be made steeper than before the amplification process, so the angle of the curved shape of the waveform of the sound signal after the clipping process can be made close to 90 degrees. Therefore, a sound signal including more high-frequency components (for example, high-frequency components in the inaudible range higher than the frequency band of the original sound signal) can be generated.

[0039] The sound signal processing device related to the 8th technical solution of the present disclosure is a sound signal processing device related to the 6th technical solution or the 7th technical solution, wherein the second signal processing unit further performs a second attenuation processing to attenuate the sound signal after the second clipping processing with a fourth gain; and the second high-range signal is the sound signal after further performing the second attenuation processing.

[0040] Therefore, the amplitude of the second clipped audio signal can be adjusted to include more high-frequency components based on the original audio signal. Thus, the second high-frequency signal with appropriately adjusted amplitude can be generated, and the high-frequency range of the original audio signal can be more appropriately expanded.

[0041] The sound signal processing device related to the 9th technical solution of the present disclosure is a sound signal processing device related to the 6th technical solution or the 7th technical solution, wherein the second signal processing unit further performs a second equalization processing to amplify or attenuate a specific frequency band of the sound signal after the second high-pass filtering processing; and the second high-range signal is the sound signal after further performing the second equalization processing.

[0042] Therefore, the frequency characteristic of the sound signal after the second high-pass filter processing can be adjusted. Thus, the second high-frequency signal with appropriately adjusted amplitude can be generated, and the high-frequency range of the original sound signal can be more appropriately expanded.

[0043] The sound signal processing device related to the 10th technical solution of the present disclosure is a sound signal processing device related to the 6th technical solution or the 7th technical solution, wherein the second signal processing unit further performs a second attenuation processing for attenuating the sound signal after the second clipping processing with a fourth gain; performs a second equalization processing for amplifying or attenuating a specific frequency band of the sound signal after the second attenuation processing; and the second high-range signal is the sound signal after further performing the second equalization processing.

[0044] Therefore, the amplitude and frequency characteristics of the sound signal after the second high-pass filter processing can be adjusted. Thus, the second high-frequency signal with appropriately adjusted amplitude can be generated, and the high frequency range of the original sound signal can be more appropriately expanded.

[0045] The sound signal processing device according to the 11th technical solution of the present disclosure is the sound signal processing device according to any one of the technical solutions of the 1st to the 5th technical solutions, and further includes a third signal processing unit, which generates a third high-range signal different from the first high-range signal based on the sound signal, the third signal processing unit (i) performs a third amplification process to amplify the sound signal with a fifth gain, (ii) performs a third clipping process to clip the sound signal after the third amplification process with a third amplitude, and (iii) performs a third high-pass filtering process on the sound signal after the third clipping process to pass a frequency band higher than a third frequency, thereby generating the third high-range signal, the third frequency being higher than the audible range, and the adding unit adds the first high-range signal and the third high-range signal to the sound signal to generate the extended sound signal.

[0046] Thus, by performing the third clipping process of clipping the sound signal after the third amplification process with the third amplitude, a sound signal including more high-frequency components based on the original sound signal can be generated. Furthermore, since the sound signal after the third clipping process is subjected to the third high-pass filter process, a third high-frequency signal having a large sound pressure in the high-frequency range can be mainly generated. Thus, by adding the first high-frequency signal and the third high-frequency signal to the original sound signal, an extended sound signal in which the high-frequency range of the original sound signal is more effectively extended can be generated.

[0047] The sound signal processing device related to the 12th technical solution of the present disclosure is the sound signal processing device related to the 11th technical solution, and the group of values ​​of the first gain and the fifth gain, the group of values ​​of the first amplitude and the third amplitude, and the group of values ​​of at least one of the first frequency and the third frequency are different from each other.

[0048] Thus, since at least one of the set of values ​​of the first gain and the fifth gain, the set of values ​​of the first amplitude and the third amplitude, and the set of values ​​of the first frequency and the third frequency is different from each other, the third high-range signal can be generated by a process different from the process of generating the first high-range signal. Therefore, the frequency characteristics of the first high-range signal and the third high-range signal can be made different. Thus, by adding the first high-range signal and the third high-range signal to the original sound signal, an extended sound signal in which the high range of the original sound signal is more effectively extended can be generated.

[0049] The sound signal processing method of the 13th technical solution of the present disclosure obtains a sound signal, generates a first high-range signal based on the sound signal, the first high-range signal includes a high-range component of a frequency band higher than a first frequency, the first frequency is higher than the audible range of a human, adds the first high-range signal to the sound signal, generates an extended sound signal with an extended high-range, and in the generation of the first high-range signal, performs a first signal processing including a first clipping processing of clipping with a first amplitude on the sound signal, and performs a first high-pass filtering processing on the sound signal after the first clipping processing to pass a frequency band higher than the first frequency, thereby generating the first high-range signal.

[0050] Thus, by performing the first clipping process of clipping the sound signal after the first amplification process with the first amplitude, a sound signal containing more high-frequency components based on the original sound signal can be generated. In addition, since the sound signal after the first clipping process is subjected to the first high-pass filter process, a first high-frequency range signal having a large sound pressure in the high-frequency range can be mainly generated, and by adding the first high-frequency range signal to the original sound signal, an extended sound signal in which the high-frequency range of the original sound signal is extended can be generated. Thus, the high-frequency range of a sound signal that does not have a 1 / f characteristic, such as a natural sound, can be easily extended so that the awkward feeling is reduced.

[0051] A program according to a fourteenth aspect of the present disclosure is a program for causing a computer to execute the sound signal processing method according to the thirteenth aspect.

[0052] Furthermore, these global or specific aspects may be implemented by a device, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM, or by any combination of a device, an integrated circuit, a computer program, and a non-transitory recording medium.

[0053] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings as appropriate. However, sometimes the necessary detailed description is omitted. For example, sometimes the detailed description of the well-known matters and the repeated description of the substantially same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art.

[0054] In addition, the inventors provide the drawings and the following descriptions in order to enable those skilled in the art to fully understand the present disclosure, and do not intend to limit the subject matter described in the claims by them.

[0055] (Implementation Method)

[0056] [1.Structure]

[0057] Figure 1 1 is a block diagram showing an example of the configuration of the sound signal processing system 1 according to the embodiment.

[0058] The sound signal processing system 1 is a system for outputting a sound in which the high-frequency range of the sound signal AS1 (original sound signal) of the sound source is expanded. Figure 1 The figure shows a sound signal processing device 100 and a speaker 200 .

[0059] The sound signal processing device 100 is a device for performing signal processing on a sound signal AS1 of a sound source to extend the high-frequency range of the sound signal AS1. The sound signal processing device 100 outputs an extended sound signal in which the high-frequency range of the sound signal AS1 is extended. The sound signal processing device 100 can be implemented by, for example, an amplifier device (preamplifier, integrated amplifier, etc.), a TV, a video playback device, an AV (Audio Visual) device such as an STB (Set Top Box), or an information processing terminal such as a PC (Personal Computer), a smart phone, or a tablet terminal.

[0060] The speaker 200 outputs an output sound based on the extended sound signal output from the sound signal processing device 100. The speaker 200 may be a passive speaker connected to an amplifier device or an active speaker with a built-in amplifier. In addition, the speaker 200 may be a speaker provided in a TV, a smart phone, or a tablet terminal. In this case, the sound signal processing system 1 may also be implemented by a single device such as a TV, a smart phone, or a tablet terminal.

[0061] <Structure of Sound Signal Processing Device>

[0062] The audio signal processing device 100 includes a communication IF (Interface) 101 , an audio input IF (Interface) 102 , a memory 103 , and a signal processing circuit 104 .

[0063] Communication IF101 is an interface for communicating with an external device. Communication IF101 can, for example, communicate with an external device to obtain a sound signal AS1 as a sound source from the external device. Communication IF101 can communicate with an external device via a network or directly with an external device. The external device for communication can be a server or a portable terminal such as a smartphone or a tablet terminal. In addition, communication IF101 can be a wireless communication interface or a wired communication interface. Wireless communication interfaces include, for example, wireless LAN, Bluetooth (registered trademark), etc. Wired communication interfaces include, for example, wired LAN. Wired communication interfaces can also include USB.

[0064] The audio input IF102 is an interface for receiving an audio signal AS1 as an audio source from an external device. The audio input IF102 includes, for example, an input terminal for receiving an analog audio signal such as an RCA terminal or a headphone terminal, and an input terminal for receiving a digital audio signal such as an optical digital terminal or a coaxial digital terminal. In addition, the audio input IF102 is not limited to an input terminal for receiving only an audio signal, but may also be an input terminal such as an HDMI (registered trademark) terminal for receiving an audio signal together with an image signal.

[0065] The sound signal AS1 as a sound source is stored in the storage 103. The storage 103 is a non-volatile storage device such as a HDD (Hard Disk Drive), an SSD (Solid State Drive), or a memory card.

[0066] Furthermore, the audio signal processing device 100 does not need to include all of the communication IF 101 , the audio input IF 102 , and the storage 103 , and only needs to include at least one of the communication IF 101 , the audio input IF 102 , and the storage 103 .

[0067] The sound signal AS1 as a sound source is, for example, a sound signal of natural sound (ambient sound) collected in advance in nature, such as the sound of a flowing river or waterfall in a mountain stream, the sound of insects or birds, etc. In addition, the sound signal AS1 as a sound source is not limited to natural sound, and may also be a sound signal of music.

[0068] The signal processing circuit 104 acquires the sound signal AS1 as a sound source, and generates an extended sound signal with an extended high-frequency range by performing sound signal processing for extending the high-frequency range on the sound signal AS1. The signal processing circuit 104 is, for example, a DSP (Digital Signal Processor). The signal processing circuit 104 includes an acquisition unit 110, first to Nth signal processing units 120a to 120X, an addition unit 130, and an output unit 140. Part or all of the functional blocks included in the signal processing circuit 104 are implemented by the DSP.

[0069] The signal processing circuit 104 may include a CPU (Central Processing Unit) or may be composed of only a CPU. Part or all of the functional blocks included in the signal processing circuit 104 may be implemented by the CPU executing a program stored in a memory or the like.

[0070] The acquisition unit 110 acquires the audio signal AS1 . Specifically, the acquisition unit 110 acquires the audio signal AS1 from at least one of the communication IF 101 , the audio input IF 102 , and the storage 103 .

[0071] The 1st to Nth signal processing units 120a to 120X are N (N is an integer greater than or equal to 3) signal processing units. The 1st to Nth signal processing units 120a to 120X generate high-range signals containing components of a frequency band higher than the frequency band of the sound signal AS1, respectively, based on the sound signal AS1. That is, the high-range signal is a signal containing components of a high-frequency band that are not included in the sound signal AS1. Each of the 1st to Nth signal processing units 120a to 120X performs different processing, so each generates a different high-range signal. That is, the 1st to Nth signal processing units 120a to 120X generate N high-range signals, and the generated N high-range signals are different signals. The specific processing of the 1st to Nth signal processing units 120a to 120X will be described later.

[0072] The adding unit 130 adds the audio signal AS1 acquired by the acquiring unit 110 and the N high-range signals generated by the N first to Nth signal processing units 120 a to 120X, and generates an extended audio signal in which the high-range is extended.

[0073] The output unit 140 outputs the extended sound signal generated by the adder 130. Specifically, the output unit 140 outputs the extended sound signal to the speaker 200. In addition, the output unit 140 may output the extended sound signal to the storage 103, and store the extended sound signal in the storage 103. In addition, the output unit 140 may output the extended sound signal to an external device via the communication IF 101.

[0074] <Configuration of the 1st to Nth Signal Processing Units>

[0075] Figure 2 It is a diagram showing an example of the structure of the first signal processing unit 120a according to the embodiment. Figure 3 This is a diagram showing an example of the waveform of the audio signal before and after each process for explaining each process performed by the first signal processing unit 120 a according to the embodiment. Figure 3 In the waveform of the sound signal in , the vertical axis represents sound pressure and the horizontal axis represents time.

[0076] The first signal processing unit 120 a includes an amplifier 121 a , a clipping unit 122 a , a filter unit 123 a , and an attenuation unit 124 a .

[0077] The amplifier 121a performs an amplification process of amplifying the sound signal AS1 acquired by the acquisition unit 110 with a gain G1. The amplifier 121a amplifies the sound signal AS1 acquired by the acquisition unit 110 with a gain G1 greater than 1. Figure 3 The sound pressure of the sound signal AS1 shown in (a) is amplified to generate Figure 3 The amplified sound signal AS2 shown in (b) of FIG. 1 is obtained. Thus, the sound pressure SP1 in the sound signal AS1 is amplified to the sound pressure SP2 (= SP1 * G1). The amplification process performed by the amplifier 121a is an example of the first amplification process. The gain G1 is an example of the first gain.

[0078] The clipping unit 122a performs a clipping process of clipping the sound signal AS2 after the amplification process performed by the amplifier 121 at the amplitude A1. That is, the clipping unit 122a performs a clipping process of clipping the sound signal AS2 after the amplification process performed by the amplifier 121 at the amplitude A1. Figure 3 As shown in (b) and (c) of FIG. 1 , the sound signal AS2 is clipped so that the sound pressure range of -A1 and below A1 is retained. Thus, a sound signal AS3 having a waveform including a shape that is linear and does not change when the sound pressure is A1 and when the sound pressure is -A1 is generated. The waveform of the sound signal AS3 is as follows: Figure 3 As shown in (c), the portion including the starting point or the end point of the linear shape where the sound pressure does not change has a curved shape, so the sound signal AS3 contains more high-frequency components. In particular, with respect to the sound signal AS2, by amplification processing, the slope of the waveform of the sound signal AS2 in the range of sound pressure above -A1 and below A1 can be made steeper than before the amplification processing. Therefore, the angle of the curved shape of the waveform of the sound signal AS3 after clipping processing can be made closer to 90 degrees than the angle of the curved shape generated by clipping of the waveform of the sound signal when the sound signal AS1 is not amplified but clipped. In addition, the slope of the waveform is made steeper, specifically, the absolute value of the slope of the tangent of the waveform is made larger. Therefore, it is possible to generate a sound signal AS3 containing more high-frequency components (for example, high-frequency components that are higher than the frequency band of the original sound signal AS1 and are in the non-audible range). The clipping processing performed by the clipping unit 122a is an example of the first clipping processing. The amplitude A1 is an example of the first amplitude.

[0079] The filter unit 123a performs high-pass filtering on the sound signal AS3 that has been clipped by the clipping unit 122a, so that a frequency band higher than the frequency f1 (high frequency range) passes through. The frequency f1 is higher than the human audible range. The frequency f1 is included in the inaudible range. In other words, the high-pass filtering is a process of cutting off the frequency band (low frequency range) below the frequency f1 of the sound signal AS3. Thus, the filter unit 123a Figure 3 As shown in (d), a sound signal AS4 is generated in which the sound pressure in the high-frequency range is greater than the sound pressure in the low-frequency range. The high-pass filter processing performed by the filter unit 123a is an example of the first high-pass filter processing. The frequency f1 is an example of the first frequency.

[0080] The attenuation unit 124a performs attenuation processing of attenuating the sound signal AS4 after the high-pass filtering processing performed by the filter unit 123a with a gain G2. For example, the attenuation unit 124a attenuates the sound signal AS4 with a gain G2 less than 1. Figure 3 The sound pressure attenuation of the sound signal AS4 shown in (d) generates Figure 3 The attenuated sound signal AS5 shown in (e) is obtained. As a result, the sound pressure SP3 of the sound signal AS4 is attenuated to the sound pressure SP4 (= SP3*G2). The sound signal AS5 is a first high-frequency signal. The attenuation process performed by the attenuation unit 124a is an example of the first attenuation process. The gain G2 is an example of the second gain. In addition, the gain G2 may be the reciprocal of the gain G1 or a value different from the reciprocal of the gain G1.

[0081] Here, the attenuation process performed by the attenuation unit 124a is performed following the high-pass filtering process performed by the filtering unit 123a, but the present invention is not limited thereto and the attenuation process may be performed following the clipping process performed by the clipping unit 122a. In this case, the high-pass filtering process is performed following the attenuation process. That is, the attenuation process may be performed after the clipping process performed by the clipping unit 122a, and may be performed before or after the high-pass filtering process.

[0082] Figure 4 It is a diagram showing an example of the structure of the second signal processing unit 120b according to the embodiment. Figure 5 This is a diagram showing an example of the waveform of the audio signal before and after each process for explaining each process performed by the second signal processing unit 120b according to the embodiment. Figure 5 In the waveform of the sound signal in , the vertical axis represents sound pressure and the horizontal axis represents time.

[0083] The second signal processing unit 120 b includes an offset unit 125 , an amplifier 121 b , a clipping unit 122 b , a filter unit 123 b , and an attenuation unit 124 b .

[0084] The offset unit 125 performs an offset process on the sound signal AS1 acquired by the acquisition unit 110 to offset the sound pressure by a predetermined amount. Figure 5 The sound pressure of the sound signal AS1 shown in (a) is added to the predetermined sound pressure ΔSP to generate Figure 5 The offset unit 125 may perform an offset process of subtracting a predetermined sound pressure from the sound pressure of the sound signal AS1.

[0085] The amplifier 121b performs an amplification process of amplifying the sound signal AS12 after the offset process performed by the offset unit 125 with a gain G3. For example, the amplifier 121b amplifies the sound signal AS12 after the offset process performed by the offset unit 125 with a gain G3 greater than 1. Figure 5The sound pressure of the sound signal AS12 shown in (b) is amplified to generate Figure 5 The amplified sound signal AS13 shown in (c) is obtained. Thus, the sound pressure SP11 of the sound signal AS12 is amplified to the sound pressure SP12 (= SP11 * G3). The amplification process performed by the amplifier 121b is an example of the second amplification process. The gain G3 is an example of the third gain.

[0086] Here, the offset processing by the offset unit 125 is assumed to be performed before the amplification processing by the amplifier 121b, but the present invention is not limited thereto and the offset processing may be performed after the amplification processing by the amplifier 121b. The offset processing may be performed before or after the amplification processing by the amplifier 121b as long as it is performed before the clipping processing by the clipping unit 122b.

[0087] The clipping unit 122b performs a clipping process of clipping the sound signal AS13 after the amplification process performed by the amplifier 121b at an amplitude of A2. Figure 5 As shown in (c) and (d) of FIG. 1 , the sound signal AS13 is clipped to keep the sound pressure range of above -A2 and below A2. Thus, a sound signal AS14 having a waveform including a shape that is linear and does not change the sound pressure when the sound pressure is A2 and when the sound pressure is -A2 is generated. The waveform of the sound signal AS14 is as follows: Figure 5 As shown in (d), the portion including the starting point or the end point of the linear shape where the sound pressure does not change has a curved shape, so the sound signal AS14 contains more high-frequency components. In particular, the sound signal AS13 is amplified, and the slope of the waveform of the sound signal AS13 in the sound pressure range above -A2 and below A2 becomes steeper than before the amplification process, so the angle of the curved shape of the waveform of the sound signal AS14 after the clipping process can be made close to 90 degrees. Therefore, the sound signal AS14 containing more high-frequency components can be generated. The clipping process performed by the clipping unit 122b is an example of the second clipping process. The amplitude A2 is an example of the second amplitude.

[0088] The predetermined sound pressure ΔSP of the offset amount by the offset portion 125 may be larger than, smaller than, or the same as the amplitude A2 of the clipping by the clipping portion 122 b .

[0089] The filter unit 123b performs high-pass filtering on the sound signal AS14 after the first clipping process, so that the frequency band (high frequency range) higher than the frequency f2 passes through, wherein the frequency f2 is higher than the human audible range. The frequency f2 is included in the inaudible range. In other words, the high-pass filtering process is a process of cutting off the frequency band (low frequency range) below the frequency f2 of the sound signal AS14. Thus, the filter unit 123b is as follows: Figure 5 As shown in (e), a sound signal AS15 is generated in which the sound pressure in the high-frequency range is greater than the sound pressure in the low-frequency range. The high-pass filter processing performed by the filter unit 123b is an example of the second high-pass filter processing. The frequency f2 is an example of the second frequency.

[0090] The attenuation unit 124b performs attenuation processing of attenuating the sound signal AS15 after the high-pass filtering processing performed by the filter unit 123b with a gain G4. For example, the attenuation unit 124b attenuates the sound signal AS15 with a gain G4 less than 1. Figure 5 The sound pressure attenuation of the sound signal AS15 shown in (e) generates Figure 5 The attenuated sound signal AS16 shown in (f) is obtained. As a result, the sound pressure SP13 of the sound signal AS15 is attenuated to the sound pressure SP14 (= SP13 * G4). The sound signal AS16 is a second high-frequency signal. The attenuation process performed by the attenuation unit 124b is an example of the second attenuation process. The gain G4 is an example of the fourth gain. In addition, the gain G4 can be the reciprocal of the gain G3 or a value different from the reciprocal of the gain G3.

[0091] Here, the attenuation process performed by the attenuation unit 124b is assumed to be performed following the high-pass filter process performed by the filter unit 123b, but the present invention is not limited thereto and the attenuation process may be performed following the clipping process performed by the clipping unit 122b. In this case, the high-pass filter process is performed following the attenuation process. That is, the attenuation process may be performed after the clipping process performed by the clipping unit 122b, and may be performed before or after the high-pass filter process.

[0092] In addition, the parameters used in the respective processes of the first signal processing unit 120a and the second signal processing unit 120b may be the same or different from each other. Specifically, the gain G1 as a parameter used in the amplification process performed by the amplifier 121a and the gain G3 as a parameter used in the amplification process performed by the amplifier 121b may be the same or different. In addition, the amplitude A1 as a parameter used in the clipping process performed by the clipping unit 122a and the amplitude A2 as a parameter used in the clipping process performed by the clipping unit 122b may be the same or different. In addition, the frequency f1 as a parameter used in the high-pass filter process performed by the filter unit 123a and the frequency f2 as a parameter used in the high-pass filter process performed by the filter unit 123b may be the same or different. In addition, the gain G2 as a parameter used in the attenuation process performed by the attenuation unit 124a and the gain G4 as a parameter used in the attenuation process performed by the attenuation unit 124b may be the same or different.

[0093] In addition, the signal processing units other than the first signal processing unit 120a and the second signal processing unit 120b among the N first to Nth signal processing units 120a to 120X may have any structure as long as they can generate high-frequency signals through processing different from that of the first signal processing unit 120a and the second signal processing unit 120b.

[0094] For example, the other signal processing units may include the same processing units as the first signal processing unit 120a, and any of the parameters used in the processing of each processing unit may be different from those of the first signal processing unit 120a. Specifically, the other signal processing units may include: an amplifier that performs an amplification process (third amplification process) of amplifying the sound signal AS1 with a gain G5; a clipping unit that performs a clipping process (third clipping process) of clipping the sound signal after the amplification process (third amplification process) with an amplitude A3; a filter that performs a high-pass filter process that passes a frequency band higher than a frequency f3, wherein the frequency f3 is higher than the audible range of a human (third high-pass filter process) for the sound signal after the clipping process (third clipping process); and an attenuation unit that performs an attenuation process that attenuates the sound signal after the high-pass filter process (third high-pass filter process) with a gain G6. Furthermore, any of the parameters used in each processing may be different from the parameters used in each processing of the first signal processing unit 120a. That is, it is sufficient that at least one of the sets of values ​​of the gain G1 and the gain G5, the set of values ​​of the amplitude A1 and the amplitude A3, the set of values ​​of the frequency f1 and the frequency f3, and the set of values ​​of the gain G2 and the gain G6 are different from each other. The other signal processing unit in this case is an example of the third signal processing unit.

[0095] In addition, the other signal processing units, for example, may also have the same processing unit as the second signal processing unit 120b, and any of the parameters used in the processing of each processing unit may be different from those of the second signal processing unit 120b. That is, the parameters used in the processing of at least one of the multiple processing units (offset unit, amplifier, clipping unit, filter unit, and attenuation unit) of the other signal processing units may be different from the parameters used in the processing of at least one of the multiple processing units (offset unit 125, amplifier 121b, clipping unit 122b, filter unit 123b, and attenuation unit 124b) of the second signal processing unit 120b corresponding to the above-mentioned at least one processing unit.

[0096] In addition, other signal processing units may also have an equalizing unit. The equalizing unit performs equalizing processing to amplify or attenuate a specific frequency band of the sound signal after high-pass filtering. Equalizing processing is a processing that performs different gain adjustments between a first frequency band and a second frequency band different from the first frequency band in the frequency of the sound signal of the processing object. Different gain adjustments can be either amplification processing and attenuation processing, or processing with different gains in the amplification processing, or processing with different gains in the attenuation processing. Therefore, the frequency characteristics of the sound signal after high-pass filtering can be adjusted. As a result, a high-frequency range signal with appropriately adjusted amplitude can be generated, and the high-frequency range of the sound signal can be appropriately expanded.

[0097] The equalization process may include attenuation in the attenuation unit. That is, the equalization process may include attenuation of the entire frequency band. In this case, the other signal processing units may not have the attenuation unit.

[0098] In addition, other signal processing units only need to include at least a clipping unit and a filtering unit among the amplification unit, the clipping unit, the filtering unit, the attenuation unit, the equalization unit, and the offset unit.

[0099] In addition, when the structures of the processing units possessed by other signal processing units are the same (combination of processing units), it is sufficient as long as at least one of the parameters used in each processing is a parameter used in each processing of the signal processing unit having the same combination of processing units and is different from a parameter used in the processing corresponding to the above at least one parameter.

[0100] Thus, the N first to Nth signal processing units 120a to 120X perform different processing depending on whether the combination of processing units is different or the combination of processing units is the same but the parameters used in the processing by the processing units are different. Thus, N different high-range signals can be generated.

[0101] [2.Action]

[0102] Next, the operation of the audio signal processing device 100 will be described.

[0103] Figure 6 1 is a flowchart showing an example of sound signal processing by the sound signal processing device 100 according to the embodiment.

[0104] First, the acquisition unit 110 acquires the audio signal AS1 ( S11 ).

[0105] Next, the first to Nth signal processing units 120a to 120X generate N high-frequency signals having a higher sound pressure in the high-frequency range than in the low-frequency range based on the audio signal AS1 ( S12 ).

[0106] Next, the adder 130 adds the audio signal AS1 acquired by the acquirer 110 and the N high-range signals generated by the N first to Nth signal processing units 120a to 120X to generate an extended audio signal with an extended high-range (S13).

[0107] Next, the output unit 140 outputs the extended audio signal generated by the adder 130 ( S14 ).

[0108] Figure 7 1 is a flowchart showing an example of a process for generating a first high-range signal among N high-range signals according to an embodiment. Figure 7 This figure shows a part of the process of step S12 for generating N high-range signals.

[0109] First, the amplifier 121 a performs an amplification process of amplifying the audio signal AS1 acquired by the acquisition unit 110 with a gain G1 ( S21 ).

[0110] Next, the clipping unit 122a performs a clipping process of clipping the audio signal AS2 amplified by the amplifier 121 at an amplitude A1 (S22).

[0111] Next, the filter unit 123a performs high-pass filtering processing on the audio signal AS3 after the first clipping processing so as to pass a frequency band (high frequency range) higher than the frequency f1 which is higher than the human audible range (S23).

[0112] Next, the attenuation unit 124a performs attenuation processing of attenuating the audio signal AS4 subjected to the high-pass filter processing by the filter unit 123a with a gain G2 (S24).

[0113] By executing the processing of steps S21 to S24 , a first high-range signal is generated.

[0114] Figure 8 1 is a flowchart showing an example of an operation of generating a second high-range signal among N high-range signals according to the embodiment. Figure 8 This figure shows a part of the process of step S12 for generating N high-range signals.

[0115] First, the offset unit 125 performs an offset process for offsetting the sound signal AS1 acquired by the acquisition unit 110 by a predetermined sound pressure amount ( S25 ).

[0116] Next, the amplifier 121 b performs an amplification process of amplifying the audio signal AS12 after the offset process performed by the offset unit 125 by a gain G3 ( S31 ).

[0117] Next, the clipping unit 122b performs a clipping process of clipping the audio signal AS13 amplified by the amplifier 121b at an amplitude of A2 (S32).

[0118] Next, the filter unit 123b performs high-pass filtering processing on the audio signal AS14 after the first clipping processing so as to pass a frequency band (high frequency range) higher than a frequency f2 higher than the human audible range (S33).

[0119] Next, the attenuation unit 124b performs attenuation processing of attenuating the audio signal AS15 after the high-pass filter processing by the filter unit 123b with a gain G4 (S34).

[0120] By executing the processing of steps S25 to S34, a second high-range signal is generated.

[0121] In the third to Nth signal processing units, the third to Nth high-range signals are also generated by performing signal processing based on the combination of the configurations of the processing units included in the signal processing units and the parameters used in the processing of the processing units.

[0122] [3. Effects, etc.]

[0123] The sound signal processing device 100 according to the present embodiment includes an acquisition unit 110, a first signal processing unit 120a, and an addition unit 130. The acquisition unit 110 acquires a sound signal AS1. The first signal processing unit 120a generates a first high-range signal including a high-range component of a frequency band higher than a first frequency (frequency f1) based on the sound signal AS1, and the first frequency (frequency f1) is higher than the audible range of a human. The addition unit 130 adds the first high-range signal to the sound signal AS1 to generate an extended sound signal having an extended high-range. The first signal processing unit 120a generates a first high-range signal by (i) performing a first signal processing including a first clipping processing of clipping with a first amplitude (amplitude A1) on the sound signal AS1, and (ii) performing a first high-pass filter processing of passing a frequency band higher than the first frequency (frequency f1) on the sound signal AS3 after the first clipping processing.

[0124] Thus, by performing the first signal processing including the first clipping processing of clipping with the first amplitude (amplitude A1) on the sound signal AS1, a sound signal containing more high-frequency components based on the sound signal AS1 can be generated. Furthermore, by performing the first high-pass filter processing on the sound signal AS3 after the first clipping processing, the first high-frequency range signal with a large sound pressure in the high-frequency range can be mainly generated, and by adding the first high-frequency range signal to the sound signal AS1, an extended sound signal in which the high-frequency range of the sound signal AS1 is extended can be generated. Thus, the high-frequency range of the sound signal AS1 that does not have the 1 / f characteristic, such as natural sound, can be easily extended so that the awkward feeling given to people is reduced.

[0125] In the audio signal processing device 100 according to the present embodiment, the first signal processing includes the first amplification processing of amplifying the audio signal AS1 with the first gain (gain G1) and the first clipping processing of the audio signal AS2 after the first amplification processing.

[0126] Thus, by the amplification process, the slope of the waveform of the sound signal AS2 in the range of sound pressure above -A1 and below A1 based on the amplitude A1 can be made steeper than before the amplification process, so the angle of the curved shape of the waveform of the sound signal AS3 after the clipping process can be made close to 90 degrees. Therefore, the sound signal AS3 containing more high-frequency components (for example, high-frequency components in the non-audible range and higher than the frequency band of the original sound signal AS1) can be generated.

[0127] In the audio signal processing device 100 according to the present embodiment, the first signal processing unit 120a further performs a first attenuation process of attenuating the audio signal AS3 after the first clipping process with a second gain (gain G2). The first high-frequency signal is the audio signal AS5 after the first attenuation process is further performed.

[0128] Therefore, the amplitude of the sound signal AS4 after the first clipping process (after the first clipping process and the first high-pass filtering process in this embodiment) can be adjusted to include more high-frequency components based on the sound signal AS1. As a result, the first high-frequency range signal with appropriately adjusted amplitude can be generated, and the high-frequency range of the sound signal AS1 can be appropriately expanded.

[0129] In addition, the sound signal processing device 100 according to the present embodiment further includes a second signal processing unit 120b. The second signal processing unit 120b generates a second high-range signal different from the first high-range signal based on the sound signal AS1. The second signal processing unit 120b generates a second high-range signal by (i) performing a second signal processing including an offset processing of offsetting a predetermined sound pressure ΔSP on the sound signal AS1, (ii) performing a second clipping processing of clipping the sound signal AS13 after the second signal processing with a second amplitude (amplitude A2), and (iii) performing a second high-pass filter processing of passing a frequency band higher than a second frequency (frequency f2) higher than the human audible range on the sound signal AS14 after the second clipping processing. The adding unit 130 adds the first high-range signal and the second high-range signal (in the present embodiment, N high-range signals including the first high-range signal and the second high-range signal are added) to the sound signal AS1 to generate an extended sound signal.

[0130] Thus, by performing the second clipping process of clipping the offset-processed and second-amplified sound signal AS13 with the second amplitude (amplitude A2), a sound signal containing more high-frequency components based on the sound signal AS1 can be generated. Since the sound signal AS3 after the first clipping process is clipped without the offset process, the even-numbered frequency components are cancelled, so it contains more odd-numbered frequency components. The sound signal AS14 after the second clipping process is clipped after the offset process, and the even-numbered frequency components are not cancelled and remain more, so it contains more even-numbered frequency components. Therefore, the frequency characteristics of the first high-range signal and the second high-range signal can be made different, and the high-range of the sound signal AS1 can be more effectively extended.

[0131] Furthermore, in the audio signal processing device 100 according to the present embodiment, the second signal processing includes the offset processing and the second amplification processing of amplifying the audio signal AS12 after the offset processing with the third gain (gain G3).

[0132] Thus, by the amplification process, the slope of the waveform of the sound signal AS12 in the range of sound pressure above -A2 and below A2 based on the amplitude A2 can be made steeper than before the amplification process, so the angle of the curved shape of the waveform of the sound signal AS14 after the clipping process can be made close to 90 degrees. Therefore, the sound signal AS14 containing more high-frequency components (for example, high-frequency components in the inaudible range higher than the frequency band of the original sound signal AS1) can be generated.

[0133] In the audio signal processing device 100 according to the present embodiment, the second signal processing unit 120b further performs a second attenuation process of attenuating the audio signal AS14 after the second clipping process with a fourth gain (gain G4). The second high-frequency signal is the audio signal AS16 after the second attenuation process is further performed.

[0134] Therefore, the amplitude of the sound signal AS15 after the second clipping process (after the second clipping process and the second high-pass filter process in this embodiment) can be adjusted to include more high-frequency components based on the sound signal AS1. As a result, the second high-frequency range signal with appropriately adjusted amplitude can be generated, and the high-frequency range of the sound signal AS1 can be more appropriately expanded.

[0135] In addition, the sound signal processing device 100 according to the present embodiment further includes a third signal processing unit. The third signal processing unit generates a third high-range signal different from the first high-range signal based on the sound signal AS1. The third signal processing unit generates a third high-range signal by (i) performing a third amplification process of amplifying the sound signal AS1 with a fifth gain (gain G5), (ii) performing a third clipping process of clipping the sound signal after the third amplification process with a third amplitude (amplitude A3), and performing a third high-pass filter process of passing a frequency band higher than a third frequency (frequency f3) higher than the human audible range on the sound signal after the third clipping process. The adding unit 130 adds the first high-range signal and the third high-range signal (in the present embodiment, N high-range signals including the first high-range signal and the third high-range signal are added) to the sound signal AS1 to generate an extended sound signal.

[0136] Thus, by performing the third clipping process of clipping the sound signal after the third amplification process with the third amplitude, a sound signal containing more high-frequency components based on the sound signal AS1 can be generated. In addition, since the third high-pass filter process is performed on the sound signal after the third clipping process, a third high-frequency signal with a large sound pressure in the high frequency range can be mainly generated. Thus, by adding the first high-frequency signal and the third high-frequency signal to the sound signal AS1, an extended sound signal in which the high frequency range of the sound signal AS1 is more effectively extended can be generated.

[0137] In addition, in the sound signal processing device 100 related to the present embodiment, the set of values ​​of the first gain (gain G1) and the fifth gain (gain G5), the set of values ​​of the first amplitude (amplitude A1) and the third amplitude (amplitude A3), and the set of values ​​of the first frequency (frequency f1) and the third frequency (frequency f3) are different from each other.

[0138] Thus, since at least one of the sets of values ​​of the first gain (gain G1) and the fifth gain (gain G5), the sets of values ​​of the first amplitude (amplitude A1) and the third amplitude (amplitude A3), and the sets of values ​​of the first frequency (frequency f1) and the third frequency (frequency f3) are different from each other, the third high-range signal can be generated by a process different from the process of generating the first high-range signal. Therefore, the frequency characteristics of the first high-range signal and the third high-range signal can be made different. Thus, by adding the first high-range signal and the third high-range signal to the sound signal AS1, an extended sound signal in which the high range of the sound signal AS1 is more effectively extended can be generated.

[0139] [4. Modifications]

[0140] It is assumed that the sound signal processing device 100 of the above-mentioned embodiment includes N first to Nth signal processing units 120a to 120X, but any configuration may be sufficient as long as at least one of the N first to Nth signal processing units 120a to 120X is included. This is because at least one high-frequency signal can be generated by at least one signal processing unit, and an extended sound signal in which the high frequency range of the sound signal AS1 is extended can be generated. That is, in the above-mentioned embodiment, it is assumed that N is an integer greater than 3, but it is not limited to this, and N may also be an integer greater than 1.

[0141] In addition, in the above-mentioned embodiment, each component of the signal processing circuit 104 may be formed by dedicated hardware, or implemented by executing a software program suitable for each component. Each component may also be implemented by a program execution unit such as a CPU or a processor reading and executing a software program recorded in a recording medium such as a hard disk or a semiconductor memory.

[0142] In addition, each component may be a circuit (or integrated circuit). These circuits may constitute one circuit as a whole, or they may be different circuits. In addition, these circuits may be general circuits or dedicated circuits.

[0143] In addition, the global or specific aspects of the present disclosure may also be implemented by a system, device, method, integrated circuit, computer program, or non-transitory recording medium such as a computer-readable CD-ROM. In addition, it may also be implemented by any combination of a system, device, method, integrated circuit, computer program, and non-transitory recording medium that can be read by a computer.

[0144] For example, the present disclosure may be implemented as a sound signal processing method executed by a sound signal processing device (computer or DSP), or may be implemented as a program for causing a computer or DSP to execute the above-mentioned sound signal processing method.

[0145] Furthermore, in the above embodiment, the processing performed by a specific processing unit may be performed by another processing unit. Furthermore, the order of multiple processing in the operation of the sound signal processing device 100 described in the above embodiment may be changed, and multiple processing may be performed in parallel.

[0146] In addition, various modifications that can be conceived by those skilled in the art to the embodiments, or embodiments achieved by arbitrarily combining the components and functions of the embodiments without departing from the gist of the present disclosure are also included in the present disclosure.

[0147] Industrial Applicability

[0148] The present disclosure is useful as a sound signal processing device or the like that can easily expand the high-frequency range of a sound signal that does not have a 1 / f characteristic, such as a sound signal of natural sound, so as to reduce the sense of discomfort to people.

[0149] Description of symbols

[0150] 1 Sound signal processing system

[0151] 100 Sound signal processing device

[0152] 101 Communication IF

[0153] 102 Sound Input IF

[0154] 103 Storage

[0155] 104 Signal Processing Circuit

[0156] 110 Acquisition Department

[0157] 120a First signal processing unit

[0158] 120b Second signal processing unit

[0159] 120X Nth signal processing unit

[0160] 121a, 121b Amplification section

[0161] 122a, 122b Clipping section

[0162] 123a, 123b filter unit

[0163] 124a, 124b Attenuation section

[0164] 125 offset

[0165] 130 Addition

[0166] 140 Output

[0167] 200 speakers

Claims

1. A sound signal processing device, wherein: have: an acquisition unit, for acquiring a sound signal; a first signal processing unit that generates, based on the sound signal, a first high-frequency signal including a high-frequency component in a frequency band higher than a first frequency, wherein the first frequency is higher than a human audible range; as well as an adding unit that adds the first high-range signal to the sound signal to generate an extended sound signal having an extended high-range, The first signal processing unit (i) performs a first signal processing including a first clipping processing of clipping with a first amplitude on the sound signal, and (ii) performs a first high-pass filtering processing of passing a frequency band higher than the first frequency on the sound signal after the first clipping processing, thereby generating the first high-range signal.

2. The sound signal processing device according to claim 1, wherein: The first signal processing includes a first amplification processing of amplifying the audio signal with a first gain, and the first clipping processing performed on the audio signal after the first amplification processing.

3. The sound signal processing device according to claim 2, wherein: The first signal processing unit further performs a first attenuation process of attenuating the sound signal after the first clipping process with a second gain. The first high-range signal is a sound signal that has been further subjected to the first attenuation process.

4. The sound signal processing device according to claim 2, wherein: The first signal processing unit further performs a first equalization process for amplifying or attenuating a specific frequency band of the audio signal after the first high-pass filter process. The first high-range signal is a sound signal that has been further subjected to the first equalization process.

5. The sound signal processing device according to claim 2, wherein: The first signal processing unit further comprises: performing a first attenuation process of attenuating the sound signal after the first clipping process with a second gain, performing a first equalization process for amplifying or attenuating a specific frequency band of the sound signal after the first attenuation process, The first high-range signal is a sound signal that has been further subjected to the first equalization process.

6. The sound signal processing device according to any one of claims 1 to 5, wherein: further, A second signal processing unit is provided, the second signal processing unit generating a second high-range signal different from the first high-range signal based on the sound signal, The second signal processing unit (i) performs a second signal processing including an offset processing of offsetting a predetermined sound pressure amount on the sound signal, (ii) performs a second clipping processing of clipping the sound signal after the second signal processing with a second amplitude, and (iii) performs a second high-pass filter processing of passing a frequency band higher than a second frequency on the sound signal after the second clipping processing, thereby generating the second high-range signal, wherein the second frequency is higher than the audible range. The adding unit adds the first high-range signal and the second high-range signal to the sound signal to generate the extended sound signal.

7. The sound signal processing device according to claim 6, wherein: The second signal processing includes the offset processing and a second amplification processing of amplifying the sound signal after the offset processing with a third gain.

8. The sound signal processing device according to claim 7, wherein: The second signal processing unit further performs a second attenuation process of attenuating the second clipped audio signal with a fourth gain. The second high-range signal is a sound signal that has been further subjected to the second attenuation process.

9. The sound signal processing device according to claim 7, wherein: The second signal processing unit further performs a second equalization process for amplifying or attenuating a specific frequency band of the audio signal after the second high-pass filter process. The second high-range signal is a sound signal that has been further subjected to the second equalization process.

10. The sound signal processing device according to claim 7, wherein: The second signal processing unit further comprises: performing a second attenuation process of attenuating the sound signal after the second clipping process with a fourth gain, performing a second equalization process for amplifying or attenuating a specific frequency band of the sound signal after the second attenuation process, The second high-range signal is a sound signal that has been further subjected to the second equalization process.

11. The sound signal processing device according to any one of claims 2 to 5, wherein: further comprising a third signal processing unit that generates a third high-range signal different from the first high-range signal based on the sound signal, The third signal processing unit (i) performs a third amplification process of amplifying the sound signal with a fifth gain, (ii) performs a third clipping process of clipping the sound signal after the third amplification process with a third amplitude, and (iii) performs a third high-pass filter process of passing a frequency band higher than a third frequency on the sound signal after the third clipping process, thereby generating the third high-range signal, wherein the third frequency is higher than the audible range. The adding unit adds the first high-range signal and the third high-range signal to the sound signal to generate the extended sound signal.

12. The sound signal processing device according to claim 11, wherein: At least one of the set of values ​​of the first gain and the fifth gain, the set of values ​​of the first amplitude and the third amplitude, and the set of values ​​of the first frequency and the third frequency is different from each other.

13. A method for processing a sound signal, wherein: Get the sound signal, generating a first high-frequency signal including a high-frequency component in a frequency band higher than a first frequency based on the sound signal, wherein the first frequency is higher than a human audible range, adding the first high-range signal to the sound signal to generate an extended sound signal having an extended high-range, In generating the first high-range signal, performing a first signal processing including a first clipping processing of clipping at a first amplitude on the sound signal, The first high-frequency-range signal is generated by performing a first high-pass filter process for passing a frequency band higher than the first frequency on the audio signal after the first clipping process.

14. A program for causing a computer to execute the sound processing method according to claim 13.

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