Nippon Telegraph and Telephone Corporation

Panasonic Corporation

Kenichi Noguchi

Hideaki Takada

Kazunori Kobayashi

Kimitaka Tsutsumi

Yoichi Haneda

Sakurako Yazawa

Takehiro Moriya

Yutaka Kamamoto

Noboru Harada

Ryosuke Sugiura

Noboru Katta

Shoichiro Saito

Takahito Kawanishi

Keisuke Hasegawa

Junichi Matsuda

Jouji Nakayama

Takahiro Hayakawa

Kouichi Furukado

Junichi Nakajima

A microphone array is a microphone array including two or more microphone holders. The two or more microphone holderseach hold one microphone. The two or more microphone holdersare separatable from each other. The two or more microphone holdersare combinable in two or more combination manners different from each other such that the two or more microphone holdersare each in contact with any one of the other microphone holdersand a distance between the two respective microphones held by two of the microphone holdersthat are in contact with each other is a predetermined distance.

Microphone array

A sound collection apparatus includes a substantially spherical base on which at least a predetermined number of recess portions are provided in a surface thereof with a predetermined interval therebetween; and a predetermined number of microphones. The predetermined number is an integer of 2 or greater. The microphones are installed on an inner bottom surface side of the recess portions one by one. Intervals between sound collecting portions of adjacent microphones are substantially equal to each other.

Sound collection apparatus

Performance of an encoding process and a decoding process for a sound signal is enhanced. A representative value calculating partcalculates, for each frequency section by a plurality of samples fewer than the number of frequency samples of a sample sequence of a frequency domain signal corresponding to an input acoustic signal, from the sample sequence of the frequency domain signal, a representative value of the frequency section from sample values of samples included in the frequency section, for each of predetermined time sections. A signal companding partobtains, for each of the predetermined time sections, a frequency domain sample sequence obtained by multiplying a weight according to a function value of the representative value by a companding function for which an inverse function can be defined and each of the samples corresponding to the representative value in the sample sequence of the frequency domain signal, as a sample sequence of a weighted frequency domain signal.

Sample sequence converter, signal encoding apparatus, signal decoding apparatus, sample sequence converting method, signal encoding method, signal decoding method and program

Provided is a sound image reproduction device, sound image reproduction method, and sound image reproduction program that can support monaural sound sources and is capable of imparting directivity to virtual sound sources in a space. An acoustic signal processing device (sound image reproduction device)that generates virtual sound sources in a space using multiple loudspeakers arranged in a straight line, includes: a focal-point position determination unitthat determines the position of each virtual sound source to generate multiple virtual sound sources in a circular arrangement; a filter-coefficient determination unitthat calculates an impulse response vector for each loudspeaker by performing an inverse Fourier transform on a driving function for each loudspeaker that is used to generate a virtual sound source at the position of each virtual sound source and in which different weights are given to some of the virtual sound sources; and a convolution calculation unitthat calculates the convolution of one inputted acoustic signal with the impulse response vector for each loudspeaker and outputs each acoustic signal to the corresponding the multiple loudspeakers.

Sound image reproduction device, sound image reproduction method, and sound image reproduction program

An acoustic signal processing deviceincludes: a focal point position determination unitthat obtains a plurality of sets of initial focal point coordinates, coordinates of the virtual sound source, and a direction of directivity thereof, and for a pair of sets of initial focal point coordinates with different polarities among the plurality of sets of initial focal point coordinates, multiplies the sets of initial focal point coordinates by a rotation matrix based on the coordinates of the virtual sound source to thereby determine sets of focal point coordinates, the rotation matrix being specified from the direction of the directivity; a circular harmonic coefficient conversion unitthat calculates weights to be applied to multipoles including the sets of focal point coordinates from a circular harmonic coefficient; a filter coefficient computation unitthat, for each of the speakers in the speaker array, computes a weighted driving function to be applied to the speaker from the sets of focal point coordinates, polarities of the sets of focal point coordinates, and the weights to be applied to the multipoles; and a convolutional operation unitthat, for each of the speakers in the speaker array, convolves the weighted driving function for the speaker into the input acoustic signal to output the output acoustic signal for the speaker.

Acoustic signal processing device, acoustic signal processing method, and acoustic signal processing program

A loudspeaker system capable of simultaneously providing listeners with a listening environment not giving them a feeling of strangeness. The loudspeaker system () comprises drive motors (toto) for so driving at least first R-channel loudspeaker () that the current first listening position is substantially included in the perpendicularly bisecting plane of a line joining the intersecting point of the first R-channel speaker () and its directivity axis and the intersecting point of the second R-channel loudspeaker () and its directivity axis and so driving at least fourth L-channel loudspeaker () that the current second listening point is substantially included in the perpendicularly bisecting plane of the line joining the intersecting point of a third L-channel loudspeaker () and its directivity axis and the intersecting point of a fourth L-channel loudspeaker () and its directivity axis. The loudspeaker system () further comprises their motor driver section ().

Speaker system

Growing community of inventors

Musashino, Japan

Kenichi Noguchi