Pioneer Electronic Corporation

Hirofumi Yanagawa

Keishi Saito

Sumio Hagiwara

Mikio Tohyama

Hiroshi Tsubonuma

Ziqing Zhang

Takatoshi Okuno

An acoustic echo erasing apparatus which generates a pseudo-echo component from an audio reception signal (a vector x.sub.1) using an adaptive filter, and removes the pseudo-echo component from an audio transmission signal (a vector y). The apparatus extracts a feedback component depending only on the audio reception signal from the audio transmission signal, and passes the audio reception signal through the adaptive filter to generate the pseudo-echo component while setting a transfer characteristic of the adaptive filter in accordance with the feedback component.

Method and apparatus for erasing acoustic echo

A plurality of speakers are arranged in line, and a plurality of digital filters are provided for the speakers. Each of the digital filters is applied with a plurality of audio signals. Characteristics of each digital filter is adjusted so as to provide patterns of directivity to each speaker dependent on the input audio signals.

Line source speaker system

First and second processing circuits are provided for carrying out a reverberation process of an input signal, and first and second filters are provided for applying amplitude characteristics to output signals of the first and second processing circuits. A first adder is provided for adding an output signal of the first processing circuit with an output signal of the second filter at opposed phase, and a second adder is provided for adding an output signal of the first filter with an output signal of second processing circuit in-phase. First and second speakers are provided to receive output signals of the first and second adders. The first and second amplitude characteristics are determined in accordance with a correlation coefficient of sound pressures of sounds from the first and second speakers.

Sound field control system

A plurality of reverberation signal generating circuits are provided for generating a plurality of reverberation signals from input audio signals of two channels. Each of the reverberation signals has a predetermined function of correlation. A pair of filters are provided for controlling the function of correlation of the reverberation signal and for applying controlled reverberation signals to reverberation speakers, thereby providing a sound field.

Sound field control system for a multi-speaker system

A speaker system including a common input terminal for receiving an audio signal to be acoustically radiated; several speaker units; several digital filters connected between the common input terminal and the speaker units, and a filter coefficient for each of the digital filters. The speaker units are arranged linearly, in a matrix form or in a honeycomb form.

Speaker system and method of controlling directivity thereof

There is disclosed a sound field correcting apparatus for adding indirect sound signals to audio signals from a decoder when a steering emphasis operation is not executed in a decoder and for limiting the addition of the indirect sound signals when the steering emphasis operation has been performed by the decoder. Thus, a reproduction sound having a proper extent feeling and a movement feeling of a sound image is obtained in accordance with a scene of a video image.

Sound field correcting apparatus

A stereo sound system for reproducing signals from two independent channels through right and left speakers. The two speakers are centrally located and propagate a lesser part of their acoustic output directly into free space. Two acoustic tunnels separately couple the major part of the outputs of the respective speakers and have their issuing ends far removed on either side of the speakers. The tunnels provide advantageous delay.

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Tokyo, Japan

Hirofumi Yanagawa