Yamaha Corporation

Yasushi Shimizu

Fukushi Kawakami

Masato Hata

Mai Koike

Akira Miki

Mikio Tohyama

Takashi Yamakawa

Atsuko Ito

Yoshikazu Honji

Akio Suyama

Hideo Miyazaki

Toru Hirai

Shinji Kishinaga

Shinjiro Yamashita

Hiroaki Furuta

Shinichi Sahara

Kunihiro Ouchi

Hiroshi Furuya

Yoshikazu Ando

Masahiro Ikeda

Whereas a high masking effect can be secured in a space to which a masking sound is emitted, the degree of a discomfort a person existing in the space suffers can be reduced. In superimposition processing, a CPUextracts sound signals in different intervals of a sound signal X-n of a human voice, superimposes the extracted sound signals on each other on the time axis, and outputs a resulting superimposed sound signal X-n. In shift and addition processing, the CPU 12 interchanges a sound signal, before a reference position, of a sound signal X-n and a sound signal, after the reference position, of the sound signal X-n (shift processing) and outputs a sound signal X-n obtained by adding together a shift-processed sound signal X'-n and the original, non-shift-processed sound signal X-n.

Masking sound generating apparatus, storage medium stored with masking sound signal, masking sound reproducing apparatus, and program

In a masker sound generation apparatus, an acquisition part acquires a sound signal, and a generation part generates a masker sound signal based on the acquired sound signal. Specifically, the generation part divides the sound signal acquired by the acquisition part into a plurality of sections each having a predetermined time length, then repeats a sorting process of sorting the divided sections as a process of changing the sequence of arrangement of the sound signal, and alters a manner of sorting the sections each time the sorting process is repeated.

Masker sound generation apparatus and program

In a masking sound generating apparatus, a band divider divides a target sound signal into a plurality of frequency bands to generate a plurality of band signals. An envelope signal generating part generates a plurality of envelope signals representing respective envelopes of the plurality of the band signals. A signal converter segments each of the plurality of the envelope signals into a plurality of frames, then specifies frames of segmented envelope signals which have an amplitude greater than a first threshold and less than a second threshold, and changes an order of the specified frames in an arrangement of the plurality of the frames. A multiplier multiplies each of the plurality of the envelope signals by a noise signal, each envelope signal having the order of the frames changed by the signal converter, and outputs the plurality of the envelope signals multiplied by the noise signal as individual band masking signals. An adder adds the individual band masking signals to output a masking sound signal capable of masking the target sound signal.

Masking sound generating apparatus, masking system, masking sound generating method, and program

In a masking sound generation apparatus, a CPU analyzes a speech utterance speed of a received sound signal. Then, the CPU copies the received sound signal into a plurality of sound signals and performs the following processing on each of the sound signals. Namely, the CPU divides each of the sound signals into frames on the basis of a frame length determined on the basis of the speech utterance speed. Reverse process is performed on each of the frames to replace a waveform of the frame with a reverse waveform, and a windowing process is performed to achieve a smooth connection between the frames. Then, the CPU randomly rearranges the order of the frames and mixes the plurality of sound signals to generate a masking sound signal.

Sound masking system and masking sound generation method

Sound picked up by a microphone of a first sound field is reproduced by a speaker of a second sound field, and a sound picked up by a microphone of the second sound field is reproduced by the speaker of the first sound field. Sound pressure detection section detects a sound pressure of a sound present in the second (or first) sound field picked up by the microphone of the second (or first) sound field, other than a sound reproduced by the speaker of the first (or second) sound field. Other sound pressure detection section detects a sound pressure with which the sound picked up by the microphone of the second (or first) sound field and reproduced by the speaker of the first (or second) sound field is picked up by the microphone of the first (or second) sound field. Sound-pressure-difference detection section adjusts a gain of an automatic gain adjustment section in such a manner that the two detected sound pressures assume a predetermined relationship. Thus, any sound picked up in one of the first and second sound fields can be reproduced in the other sound field with an enhanced sense of unity and connection between the two sound fields.

Picked-up-sound recording method and apparatus

A reflection sound generator has a first filter of Finite Impulse Response (FIR) type that is provided with a first set of parameters representing a first distribution pattern of reflection sounds, and a second FIR-type filter provided with a second set of parameters representing a second distribution pattern of additional reflection sounds. The first distribution pattern has a time length sufficient to cover an initial reflection sound and subsequent reverberant reflection sounds which are distributed at intervals along the time. The first filter executes convolution operation of sample data of an input sound by the first set of parameters to generate first data containing a sequence of reflection sounds of the input sound. The second filter executes convolution operation of the first data by the second set of parameters to generate second data containing additional reflection sounds which fill the intervals of the reflection sounds of the input sound.

Reflection sound generator with series of main and supplementary FIR filters

A space surrounding a sound source (S) which is set in a sound field ( ) to be reproduced is divided into sound source element regions (S to Sn), and a space surrounding a sound receiving point (R) is divided into sound receiving element regions (R to Rm). An impulse response when a sound radiated from the sound source (S) is emitted from one of the sound source element regions (S to Sn), passes through the sound field ( ), enters one of the sound receiving element regions (R to Rm), and then reaches the sound receiving point (R) is obtained for each of combinations of the sound source element regions (S to Sn) and the sound receiving element regions (R to Rm). A sound emitted from a real sound source (Sr) in an arbitrary real space ( ) is picked up by microphones (MC to MCn) placed correspondingly with the sound source element regions (S to Sn). In an FIR matrix circuit ( ), the pickup signals are respectively subjected to a convolution operation with impulse responses which are obtained for each of the sound source element regions (S to Sn) in corresponding directions.

Sound field reproducing method and apparatus for the same

A sound field control unit includes a microphone collecting sound about a self-unit, a collected sound signal input-output terminal for outputting a collected sound signal of the self-unit to outside of the self-unit and inputting a collected sound signal of other units to the self-unit, a collected sound signal switch for switching the collected sound signal collected by the self-unit and that collected by the other units sequentially and repeatedly, an FIR filter for producing a reflected sound component of the collected sound signals provided by the switch and imparting it to the collected sound signals, an amplifier for amplifying the imparted reflected sound component and the collected sound signal, an equalizer provided in a signal path between an output terminal of the collected sound signal switch and an input terminal of the amplifier for adjusting frequency characteristic of a signal flowing through the signal path, and a loudspeaker for reproducing the amplified output signal. These components are assembled integrally together in the self-unit and the self-unit is adapted to be connected to the other units through the collected sound signal input-output terminal by means of transmission cables.

Sound field control unit and sound field control device

A sound field control device for simulating a sound field of a small space such as a concert hall in a large space such as an open outdoor space and a large indoor space comprises loudspeakers for controlling a sound field disposed at or in the vicinity of positions in a real space corresponding to positions on a hypothetical peripheral plane which defines a hypothetical space in the real space, and a hypothetical reflected sound synthesizing section for synthesizing hypothetical reflected sounds on the basis of the sounds from a real sound source and supplying the synthesized hypothetical reflected sounds to the loudspeakers. The hypothetical reflected sounds are synthesized so that they will simulate sounds which are emanated from the real sound source and reflected from the hypothetical peripheral plane of the hypothetical space. A natural sound field in which one feels as if he was in an indoor concert hall can be obtained in the whole hypothetical space.

Sound field control device and method for controlling a sound field

An acoustic analysis device using a reduced scale model comprises a model of a reduced scale of 1/n, a loudspeaker and a microphone provided in the model, a sound signal forming circuit for forming a signal to be radiated by AD-converting an analog signal to be measured at a predetermined sampling frequency, storing the converted signal in a first RAM, reading out the stored signal at a first sampling clock and DA-converting the read out signal, a collected sound reproducing circuit for reproducing collected sound by AD-converting an output signal from the sound collecting device at a second sampling clock, storing the converted signal in a second RAM and reading out the stored signal at a third sampling clock, a sampling clock control circuit for setting the first sampling clock frequency at a value which is n times as high as the predetermined sampling frequency and setting the second sampling clock frequency at a value which is n times as high as the third sampling clock frequency, and an acoustic analysis circuit for acoustically analizing the output of the collected sound reproducing circuit. A frequency conversion device used for the acoustic analysis device comprises the above described sound signal forming circuit, collected sound reproducing circuit and sampling clock control circuit.

Acoustic analysis device and a frequency conversion device used therefor

A system for controlling the second field in auditorium having the feature that stage and audience seating areas are different acoustically, which includes a first assisted acoustics system whereby acoustical energy from the stage area is input, and then controlled acoustic energy is supplied to the audience seating area, and a second assisted acoustics which is provided independently of the first electronic acoustical augmentation system, whereby acoustical energy from the audience seating area is input, and then controlled acoustic energy is supplied to the stage area. Each assisted acoustics system includes acoustic energy input devices and acoustic energy output devices whereby a uniform rate of power decay coefficient can be effected throughout the hall, including spaces under balconies and the like. Significantly improved the degree of acoustic similarity between the stage area and audience seating area is achieved by controlling reverberation characteristics.

Method and apparatus for controlling the sound field in auditoriums

A reverberation imparting device for electro-acoustically enhancing reverberation in acoustic space comprises a microphone disposed in the acoustic space, a loudspeaker disposed in the acoustic space for diffusing the sound picked up by the microphone, and feedback means comprising a signal processing circuit for electrically processing an electric signal corresponding to the sound picked up by the microphone, an output of the signal processing circuit being supplied to the loudspeaker. The microphone, feedback means and loudspeaker form a feedback loop. The signal processing circuit comprises a circuit for subjecting impulse responses of finite length to a convolution operation. Time axis of reflected sounds is extended and extension of reverberation time thereby is realized without depending upon loop gain. Density of reflected sounds is increased by subjecting impulse responses of finite length to a convolution operation whereby separation of reflected sounds is prevented.

Reverberation imparting device

A method of recording and reproducing video and sound information using plural recording devices and plural reproducing devices is described. An original space in which video and sound information are to be recorded is divided into plural sections. A video recording device and a corresponding sound recording device are provided for each section of the original space. A reproduction space in which video and sound information are to be reproduced is divided into plural sections corresponding to the plural sections of the original space. Synchronous operation of plural video reproducing devices is performed simultaneously with synchronous operation of plural sound reproducing devices so that the picture and sound of each section of the original space are reproduced simultaneously in a corresponding section of the reproduction space. In this manner, synchronization of picture and sound is easily achieved, and the picture and sound of the original space are reproduced with high fidelity.

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Hamamatsu, Japan

Yasushi Shimizu