Signal processing device, signal processing method and program

Abstract

To provide a signal processing device which can generate sound data containing frequency components of 20 kHz or higher.SOLUTION: A signal processing device 10 comprises: an acquisition unit 11 which acquires sound data; a pitch control unit 12 which controls the pitch of the acquired sound data to be n times of the original (n is real number larger than 1); an extraction unit 13 which extracts frequency components of 20 kHz or higher included in the sound data in which the pitch is controlled; an addition unit 14 which adds the extracted frequency components to the acquired sound data; and an output unit 15 which outputs the sound data to which the extracted frequency components are added.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] It is known that by applying inaudible sound containing frequency components of 20 kHz or more to a person, it is possible to obtain effects such as improving cerebral blood flow and improving mental and physical conditions. Such effects are called the hypersonic effect. For example, Patent Document 1 discloses a sound generating device that generates sounds that can obtain such effects. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-313610 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technique disclosed in the above Patent Document 1 requires the preparation in advance of sound data that includes frequency components of 20 kHz or more, such as the sounds of gamelan instruments.

[0005] Therefore, the present disclosure provides a signal processing device and the like capable of generating sound data including frequency components of 20 kHz or more. [Means for solving the problem]

[0006] A signal processing device according to one embodiment of the present disclosure includes an acquisition unit that acquires sound data, a pitch control unit that controls the pitch of the acquired sound data by a factor of n (n is a real number greater than 1), an extraction unit that extracts frequency components of 20 kHz or higher contained in the pitch-controlled sound data, an addition unit that adds the extracted frequency components to the acquired sound data, and an output unit that outputs the sound data to which the extracted frequency components have been added. Effect of the Invention

[0007] According to a signal processing device according to an embodiment of the present disclosure, sound data including frequency components of 20 kHz or higher can be generated. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a configuration diagram illustrating an example of a signal processing device according to an embodiment. [Diagram 2] 10 is a graph showing an example of frequency characteristics of acquired sound data. [Diagram 3] 11 is a graph showing an example of frequency characteristics of an extracted 20 kHz frequency component. [Figure 4] 11 is a graph showing an example of frequency characteristics of sound data to which an extracted frequency component of 20 kHz has been added. [Diagram 5] 13 is a flowchart illustrating an example of a signal processing method according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Embodiment) Hereinafter, a signal processing device according to an embodiment will be described with reference to the drawings.

[0010] FIG. 1 is a configuration diagram showing an example of a signal processing device 10 according to an embodiment.

[0011] The signal processing device 10 is a device for generating sound data including frequency components of 20 kHz or more from acquired sound data. It is known that a hypersonic effect that improves the mental and physical state is obtained by providing a person with a sound including frequency components of 20 kHz or more, and the signal processing device 10 is a device for generating sound data for obtaining the hypersonic effect. The signal processing device 10 includes an acquisition unit 11, a pitch control unit 12, an extraction unit 13, an addition unit 14, and an output unit 15. The signal processing device 10 includes a processor and a memory. The memory is a ROM (Read Only Memory) and a RAM (Random Access Memory), etc., and can store a program executed by the processor. The acquisition unit 11, the pitch control unit 12, the extraction unit 13, the addition unit 14, and the output unit 15 are realized by a processor that executes a program stored in the memory, etc.

[0012] The acquisition unit 11 acquires sound data. The sound data may be sound data that does not include frequency components of 20 kHz or more. For example, the sound data may be music data or environmental sound data. For example, the sound data may be acquired from a music source such as a CD (Compact Disc). The sound data recorded on a CD is data with a sampling frequency of 44.1 kHz, 16 bits, and 2 channels. Although details will be described later, the addition unit 14 adds frequency components of 20 kHz or more to the sound data acquired by the acquisition unit 11, whereas when the sampling frequency is 44.1 kHz, only frequency components up to 22.05 kHz, which is half the sampling frequency, can be added. Therefore, when acquiring sound data from a CD, the acquisition unit 11 performs upsampling on the acquired sound data. As a result, for example, sound data (for example, a high-resolution sound source) with a sampling frequency of 192 kHz, 24 to 32 bits, and 2 channels can be generated, and frequency components up to 96 kHz can be added to the sound data. The acquisition unit 11 may directly acquire a high-resolution sound source or the like as sound data, and in this case, the acquisition unit 11 does not need to perform upsampling.

[0013] The pitch control unit 12 controls the pitch (sound height) of the sound data acquired by the acquisition unit 11 to n times (n is a real number greater than 1). By multiplying the pitch of the sound data by n, the frequency components of the sound data are shifted to the n times higher frequency side as a whole. The value of n is not particularly limited, but is set to a value such that the pitch-controlled sound data includes frequency components of 20 kHz or more. For example, the pitch control unit 12 may acquire the maximum frequency component included in the sound data, and when the maximum frequency component is smaller than 20 kHz, set n to a value equal to or greater than the value obtained by dividing 20 kHz by the maximum frequency component. For example, n may be 2 to the power of m (m is an integer equal to or greater than 1). In other words, the pitch control unit 12 may control the pitch of the acquired sound data to 2 to the power of m (2 times, 4 times, 8 times, ..., etc.). In addition, the degree of improvement effect of the mental and physical state obtained may differ depending on the value of m. Therefore, the signal processing device 10 may include an input unit that receives information indicating the degree of improvement effect on the mental and physical state that the user desires, and the pitch control unit 12 may control the value of m according to the information received by the input unit. This allows the user to obtain the degree of improvement effect that the user desires.

[0014] It should be noted that pitch control section 12 may control the sound pressure level in addition to the pitch. In this case, pitch control section 12 may increase or decrease the sound pressure level.

[0015] The extraction unit 13 extracts frequency components of 20 kHz or more contained in the pitch-controlled sound data. The extraction unit 13 is, for example, a high-pass filter. The extraction unit 13 is realized by, for example, a digital filter, but may be realized by an analog filter. The extraction unit 13 may extract frequency components of 40 kHz or more as frequency components of 20 kHz or more contained in the pitch-controlled sound data.

[0016] Note that the extraction unit 13 may first extract frequency components equal to or higher than a specific frequency (e.g., 4 kHz) contained in the acquired sound data, and then the pitch control unit 12 may multiply the extracted frequency components by n (e.g., 10 times). In this manner, frequency components equal to or higher than 20 kHz can also be extracted.

[0017] The adder 14 adds the frequency components extracted by the extractor 13 to the sound data acquired by the acquirer 11. This makes it possible to generate sound data including frequency components of 20 kHz or higher.

[0018] The output unit 15 outputs sound data obtained by adding the frequency components extracted by the extraction unit 13 to the addition unit 14. For example, the output unit 15 outputs the sound data to a speaker or the like. This allows the user to hear the sound (music, environmental sound, etc.) indicated by the sound data, and at the same time, obtain the hypersonic effect.

[0019] Next, a specific example of sound data including frequency components of 20 kHz or more will be described with reference to FIGS.

[0020] FIG. 2 is a graph showing an example of frequency characteristics of acquired sound data.

[0021] FIG. 3 is a graph showing an example of the frequency characteristics of the extracted 20 kHz frequency component.

[0022] FIG. 4 is a graph showing an example of the frequency characteristics of sound data to which the extracted 20 kHz frequency component has been added.

[0023] For example, it is assumed that the acquisition unit 11 acquires sound data as shown in Fig. 2. For example, the acquired sound data is 32-bit, 2-channel sound data with a sampling frequency of 192 kHz. As shown in Fig. 2, it can be seen that the acquired sound data does not include frequency components of 20 kHz or higher.

[0024] Next, the pitch control unit 12 controls the pitch of the acquired sound data to 10 times, and the extraction unit 13 extracts frequency components of 20 kHz or more contained in the sound data whose pitch has been controlled to 10 times, resulting in the extraction of frequency components as shown in FIG.

[0025] Then, the adder 14 adds the extracted frequency components (frequency components shown in FIG. 3) to the acquired sound data (sound data shown in FIG. 2). This makes it possible to generate sound data as shown in FIG. 4. As shown in FIG. 4, it can be seen that sound data including frequency components of 20 kHz or more has been generated.

[0026] In this way, sound data including frequency components of 20 kHz or higher can be generated from sound data that does not include frequency components of 20 kHz or higher.

[0027] (summary) The signal processing device 10 includes an acquisition unit 11 that acquires sound data, a pitch control unit 12 that controls the pitch of the acquired sound data to n times (n is a real number greater than 1), an extraction unit 13 that extracts frequency components of 20 kHz or more contained in the pitch-controlled sound data, an addition unit 14 that adds the extracted frequency components to the acquired sound data, and an output unit 15 that outputs the sound data to which the extracted frequency components have been added.

[0028] According to this, even if the acquired sound data does not contain frequency components of 20 kHz or more, frequency components of 20 kHz or more can be generated by multiplying the pitch by n. However, if pitch-controlled sound data is output as is, there is a risk that audible range sounds will become unpleasant. Therefore, frequency components of 20 kHz or more are extracted from the pitch-controlled sound data, and the frequency components of 20 kHz or more are added to the acquired original sound data. This makes it possible to generate sound data that contains frequency components of 20 kHz or more while keeping the audible range sounds unchanged from the original sound data (i.e., suppressing deterioration in the quality of the audible range sounds).

[0029] The pitch control section 12 may control the pitch of the acquired sound data to be multiplied by 2 to the power of m (m is an integer equal to or greater than 1).

[0030] Although frequency components above 20 kHz are inaudible sounds, if the tonality of the inaudible sounds is different from that of the audible sounds, sounds containing frequency components above 20 kHz may give a strange feeling to the person who is given the sounds. Therefore, by controlling the pitch of the acquired sound data to the mth power of 2, sound data containing frequency components above 20 kHz that have the same tonality as audible sounds can be generated.

[0031] The extraction unit 13 may extract frequency components of 40 kHz or more contained in the pitch-controlled sound data.

[0032] It is said that it is difficult to obtain the hypersonic effect with frequency components between 20kHz and 40kHz. Therefore, by extracting frequency components above 40kHz contained in pitch-controlled sound data, it is possible to generate sound data containing frequency components above 40kHz that are easy to obtain the hypersonic effect.

[0033] (Other embodiments) As described above, the embodiment has been described as an example of the technology according to the present disclosure. However, the technology according to the present disclosure is not limited to this, and can be applied to an embodiment in which appropriate modifications, substitutions, additions, omissions, etc. are made. For example, the following modified examples are also included in one embodiment of the present disclosure.

[0034] For example, the present disclosure can be realized not only as the signal processing device 10, but also as a signal processing method including steps (processing) performed by each of the components constituting the signal processing device 10.

[0035] FIG. 5 is a flowchart showing an example of a signal processing method according to another embodiment.

[0036] As shown in FIG. 5, the signal processing method includes an acquisition step of acquiring sound data (step S11), a pitch control step (step S12) of controlling the pitch of the acquired sound data by a factor of n (n is a real number greater than 1), an extraction step (step S13) of extracting frequency components of 20 kHz or more contained in the pitch-controlled sound data, an addition step (step S14) of adding the extracted frequency components to the acquired sound data, and an output step (step S15) of outputting the sound data to which the extracted frequency components have been added.

[0037] For example, the steps of the signal processing method may be executed by a computer (computer system), and the present disclosure may be realized as a program for causing a computer to execute the steps included in the signal processing method.

[0038] Furthermore, the present disclosure can be realized as a non-transitory computer-readable recording medium, such as a CD-ROM on which the program is recorded.

[0039] For example, when the present disclosure is realized by a program (software), each step is executed by executing the program using hardware resources such as a computer's CPU, memory, input / output circuitry, etc. In other words, each step is executed by the CPU acquiring data from memory or input / output circuitry, etc., performing calculations, and outputting the results of calculations to memory or input / output circuitry, etc.

[0040] Furthermore, each of the components included in the signal processing device 10 of the above embodiment may be realized as a dedicated or general-purpose circuit.

[0041] Furthermore, each of the components included in the signal processing device 10 according to the above embodiment may be realized as an LSI (Large Scale Integration) integrated circuit (IC: Integrated Circuit).

[0042] Furthermore, the integrated circuit is not limited to an LSI, and may be realized by a dedicated circuit or a general-purpose processor. A programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor in which the connections and settings of circuit cells within an LSI can be reconfigured may also be used.

[0043] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or a different derivative technology, naturally, each component included in the signal processing device 10 may be integrated into an integrated circuit using that technology.

[0044] In addition, the present disclosure also includes forms obtained by applying various modifications to the embodiments that a person skilled in the art may conceive, and forms realized by arbitrarily combining the components and functions of each embodiment within the scope that does not deviate from the spirit of the present disclosure. [Industrial Applicability]

[0045] The present disclosure can be applied, for example, to an audio reproduction device that reproduces sound and the like. [Explanation of symbols]

[0046] 10 Signal Processing Device 11 Acquisition Department 12 Pitch control section 13 Extraction part 14 Addition section 15 Output section

Claims

1. An acquisition unit that acquires sound data; a pitch control unit that controls the pitch of the acquired sound data to n times (n is a real number greater than 1); an extraction unit that extracts frequency components of 20 kHz or more contained in the pitch-controlled sound data; an adder that adds the extracted frequency components to the acquired sound data; an output unit that outputs sound data to which the extracted frequency components have been added; An input unit that receives information indicating a degree of improvement effect of a mental and physical condition that a user desires to obtain, The pitch control unit controls the pitch of the acquired sound data in accordance with the information received by the input unit. Signal processing device.

2. The pitch control unit controls the pitch of the acquired sound data to a power of 2 (m is an integer equal to or greater than 1). The signal processing device according to claim 1 .

3. The extraction unit extracts frequency components of 40 kHz or more contained in the pitch-controlled sound data.

3. A signal processing device according to claim 1 or 2.

4. An acquisition step of acquiring sound data; a pitch control step of controlling the pitch of the acquired sound data by a factor of n (n is a real number greater than 1); an extraction step of extracting frequency components of 20 kHz or more contained in the pitch-controlled sound data; an adding step of adding the extracted frequency components to the acquired sound data; an output step of outputting sound data to which the extracted frequency components have been added; An input step of receiving information indicating a degree of improvement effect of a mental and physical condition that a user desires to obtain, In the pitch control step, the pitch of the acquired sound data is controlled in accordance with the information received in the input step. Signal processing methods.

5. A program for executing the signal processing method according to claim 4.

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