Abstract: 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.

Abstract: A method for controlling a frequency response having a bell-shaped amplitude characteristic of a filter that is configured to process an audio signal includes preparing a high-frequency parameter related to a high-frequency side characteristic on a high-frequency side of the frequency response, and a low-frequency parameter related to a low-frequency side characteristic on a low-frequency side of the frequency response, independently changing the high-frequency parameter or the low-frequency parameter in accordance with a first change instruction, changing both of the high-frequency parameter and the low-frequency parameter in conjunction with each other in accordance with a second change instruction, and controlling a slope on the high-frequency side and a slope on the low-frequency side of the bell-shaped amplitude characteristic of the frequency response, by using the high-frequency parameter and the low-frequency parameter.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A speaker array apparatus capable of performing directivity control with ease even when sound emission is performed based on audio signals of different frequency ranges. The speaker array apparatus includes a speaker unit for emitting high-frequency range sound, and another speaker unit for emitting low- and high-frequency range sound. A signal processed by a high pass filter is used for generation of both audio signals used by these speaker units to emit the high-frequency range sounds. Since both the audio signals are rotated in phase similarly to each other, the phases of audio signals supplied to both the speaker units are in coincidence with each other in high-frequency range, which makes it easy to carry out directivity control.

Abstract: Calculation is performed for sound paths 112-1, 114-1 along which sounds emitted from a sound emitting point 104 in an acoustic space 102 are reflected and delivered to a sound receiving point 106. By the calculation, entering angles eR1, eR2 by which the sound paths enter the front side 106a of the sound receiving point 106 are obtained. Calculation is then performed to obtain angles by which respective speakers 52C, 52L, 52R, 52SR, 52SL of a 5.1 surround system are arranged in a listening room, with the front side 106a of the sound receiving point 106 centered thereon. Audio signals on the respective sound paths are distributed among channels for any two speakers. Consequently, sharp localization of sound images is achieved, requiring less calculation in simulating acoustic characteristics of the acoustic space 102 in which the sound emitting point 104 for emitting sounds and the sound receiving point 106 for receiving the sounds are placed.

Abstract: Calculation is performed for sound paths 112-1, 114-1 along which sounds emitted from a sound emitting point 104 in an acoustic space 102 are reflected and delivered to a sound receiving point 106. By the calculation, entering angles eR1, eR2 by which the sound paths enter the front side 106a of the sound receiving point 106 are obtained. Calculation is then performed to obtain angles by which respective speakers 52C, 52L, 52R, 52SR, 52SL of a 5.1 surround system are arranged in a listening room, with the front side 106a of the sound receiving point 106 centered thereon. Audio signals on the respective sound paths are distributed among channels for any two speakers. Consequently, sharp localization of sound images is achieved, requiring less calculation in simulating acoustic characteristics of the acoustic space 102 in which the sound emitting point 104 for emitting sounds and the sound receiving point 106 for receiving the sounds are placed.

Abstract: Calculation is performed for sound paths 112-1, 114-1 along which sounds emitted from a sound emitting point 104 in an acoustic space 102 are reflected and delivered to a sound receiving point 106. By the calculation, entering angles ?R1, ?R2 by which the sound paths enter the front side 106a of the sound receiving point 106 are obtained. Calculation is then performed to obtain angles by which respective speakers 52C, 52L, 52R, 52SR, 52SL of a 5.1 surround system are arranged in a listening room, with the front side 106a of the sound receiving point 106 centered thereon. Audio signals on the respective sound paths are distributed among channels for any two speakers. Consequently, sharp localization of sound images is achieved, requiring less calculation in simulating acoustic characteristics of the acoustic space 102 in which the sound emitting point 104 for emitting sounds and the sound receiving point 106 for receiving the sounds are placed.

Abstract: A speaker array apparatus capable of performing control to narrow the directivity angle of low-frequency range sounds, without causing a speaker array to be large in size. An audio signal input to the speaker array apparatus is divided into an audio signal in which low-frequency range components of the input audio signal are included and an audio signal in which low-frequency range components thereof are attenuated, and the former audio signal is signal-processed by a directivity controller. Based on the processed audio signal, sounds are emitted from speakers disposed at four corners of the speaker array, whereby the directivity angle of acoustic beam in low-frequency range can be made narrower than when sounds are emitted from all the speakers of the speaker array.

Abstract: A speaker array apparatus capable of performing directivity control with ease even when sound emission is performed based on audio signals of different frequency ranges. The speaker array apparatus includes a speaker unit for emitting high-frequency range sound, and another speaker unit for emitting low- and high-frequency range sound. A signal processed by a high pass filter is used for generation of both audio signals used by these speaker units to emit the high-frequency range sounds. Since both the audio signals are rotated in phase similarly to each other, the phases of audio signals supplied to both the speaker units are in coincidence with each other in high-frequency range, which makes it easy to carry out directivity control.

Abstract: Calculation is performed for sound paths 112-1, 114-1 along which sounds emitted from a sound emitting point 104 in an acoustic space 102 are reflected and delivered to a sound receiving point 106. By the calculation, entering angles ?R1, ?R2 by which the sound paths enter the front side 106a of the sound receiving point 106 are obtained. Calculation is then performed to obtain angles by which respective speakers 52C, 52L, 52R, 52SR, 52SL of a 5.1 surround system are arranged in a listening room, with the front side 106a of the sound receiving point 106 centered thereon. Audio signals on the respective sound paths are distributed among channels for any two speakers. Consequently, sharp localization of sound images is achieved, requiring less calculation in simulating acoustic characteristics of the acoustic space 102 in which the sound emitting point 104 for emitting sounds and the sound receiving point 106 for receiving the sounds are placed.

Abstract: A sound apparatus includes: a sound output that forms sound waves having opposite phases in a front direction and a rear direction, respectively; a front microphone that collects the sound wave formed in the front direction; a rear microphone that collects the sound wave formed in the rear direction; and a signal processor that combines the signal collected by the front microphone and the signal collected by the rear microphone and outputs the resultant signal.

Abstract: A reverberation generating apparatus is designed for applying a reverberation effect to an acoustic signal for output based on sampling data representative of an impulse response waveform. In the apparatus, a first convolution operating section convolutes the acoustic signal with sampling data corresponding to an initial period of the impulse response waveform so as to generate an initial acoustic signal. The initial period of the impulse response waveform is determined from a point of impulse sound emission to a point after a lapse of a specified time. A second convolution operating section convolutes the acoustic signal with sampling data corresponding to a selected period of the impulse response waveform so as to generate an additional acoustic signal. An attenuation operating section recurrently outputs the additional acoustic signal while attenuating the additional acoustic signal so as to generate a late acoustic signal.