Yamaha Corporation

Kenji Ishizuka

Kenichi Tamiya

Kazunobu Kondo

Toshifumi Kunimoto

Yu Takahashi

Hiroomi Shidoji

Shinichiro Kaneko

Yoshifumi Mizuno

Takashi Mita

An audio processing method obtains observed envelopes of picked-up sound signals including a first observed envelope representing a contour of a first sound signal including a first target sound from a first sound source and a second spill sound from a second sound source and a second observed envelope representing a contour of a second sound signal including a second target sound from the second sound source and a first spill sound from the first sound source; and generates, based on the observed envelopes, output envelopes including a first output envelope representing a contour of the first target sound in the first observed envelope and a second output envelope representing a contour of the second target sound in the second observed envelope, using a mix matrix including a mix proportion of the second spill sound in the first sound signal and a mix proportion of the first spill sound in the second sound signal.

Audio processing method, audio processing system, and computer-readable medium

In a control method of controlling a frequency response of a filter for processing an audio signal, the frequency response is defined by an amplitude characteristic and a phase characteristic. The control method includes: acquiring a target amplitude characteristic, a target phase characteristic, and a latency value; obtaining a first frequency response in accordance with the target amplitude characteristic and the target phase characteristic; obtaining a second frequency response by modifying the first frequency response so that a latency of the second frequency response satisfies the latency value; and obtaining a third frequency response to be set for the filter by correcting the second frequency response, the second frequency response being corrected so as to reduce a difference between (i) an amplitude characteristic of the second frequency response and (ii) the target amplitude characteristic.

Control method, control system, and storage medium

An amplifier performs analog amplification on a signal I_A with a gain corresponding to a state GS and outputs the amplified signal as a signal M_A. An ADC converts the signal M_A to a digital signal and outputs the digital signal as a signal M_D. Analog comparators and a down-determination unit detect that the signal M_A exceeds a first level, and cause the state GS to transition to a state of gain of the next lower stage. Digital comparators and an up-determination unit detect that the signal M_D has been continuously lower than a second level for a predetermined period, and cause the state GS to transition to a state of gain of the next higher stage. The restoration circuit performs digital amplification on the signal M_D with a gain corresponding to the gain of the amplifier and outputs the amplified signal as a signal O_D.

A/D conversion device and A/D conversion method

An appropriate level index is obtained from an input audio waveform. An audio signal processing method includes detecting one or more level values in each of a plurality of attack sections included in an audio signal including the plurality of attack sections and a plurality of non-attack sections different from the plurality of attack sections; and generating a histogram of the detected level values in each of the plurality of attack sections, the generated histogram excluding level values of the plurality of non-attack sections.

Audio signal processing method, apparatus, and program

A method for controlling an FIR filter that processes sound signals based on setting of a band filter includes receiving, from a user, an instruction for control data that indicate a gain parameter of an amplitude characteristic corresponding to a transfer function represented as a function of angular frequency, generating a first amplitude characteristic that is an amplitude characteristic of the band filter, as a basis of an amplitude characteristic of the FIR filter, in accordance with the control data, receiving an instruction for a gain limit value from the user, limiting a gain curve of the first amplitude characteristic so as to be within the gain limit value that has been instructed, thereby acquiring a second amplitude characteristic, and setting filter coefficients of the FIR filter based on the second amplitude characteristic.

Method and device for controlling fir filter

A method for controlling an FIR filter includes generating, based on operation information, a first and second control data, generating a second amplitude characteristic, and setting filter coefficients of the FIR filter based on the second amplitude characteristic. The first control data indicates an amount of expansion/compression in a frequency axis direction of a first amplitude characteristic that corresponds to a predetermined transfer function that is expressed as a function of an angular frequency, and the amount of expansion/compression is an integer value or a non-integer value. The second control data indicates an amount of shift in the frequency axis direction of the first amplitude characteristic. The second amplitude characteristic is generated by expanding/compressing the first amplitude characteristic in the frequency axis direction in accordance with the first control data and shifting the first amplitude characteristic in the frequency axis direction in accordance with the second control data.

Method and device for controlling FIR filter

A system for implementing filter control includes an audio processing apparatus, an analog-to-digital converter, a digital-to-analog converter, a filter, and a processor. The processor is configured to receive parameters that define a frequency response in a given frequency bandwidth. The processor is also configured to generate, based on the parameters, a response curve representative of a frequency response of a filter. The processor is also configured to generate, based on the response curve, a filter coefficient of the filter. The lower inclined portion corresponds to, within the given frequency bandwidth, a frequency bandwidth that is lower than a frequency bandwidth corresponding to the upper inclined portion.

System for implementing filter control, filter controlling method, and frequency characteristics controlling method

A method for setting a filter frequency response includes: dividing a target frequency band into multiple first partial bands at a frequency corresponding to an intersection between a first line representative of a target spectrum envelope and a second line representative of a first spectrum envelope derived from smoothing a measured frequency spectrum; and setting a frequency response of a filter corresponding to a first partial band specified by an operator from among the multiple first partial bands, in accordance with a setting operation for setting an adjustment amount performed by the operator with respect to the specified first partial band.

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Hamamatsu, Japan

Kenji Ishizuka