Matsushita Electric Industrial Co., Ltd.

Mitsuhiko Serikawa

Akihisa Kawamura

Masaharu Matsumoto

Hiroko Numazu

Katsuaki Sato

Takeshi Norimatsu

Mikio Oda

Hiroyuki Takewa

Sawako Usuki

Taro Katayama

Seiichi Ishikawa

Ryou Tagami

Hiroko Yoshida

Ryo Tagami

Tomokazu Ishikawa

Mineo Tsushima

Yoshihisa Nakatoh

Shuichi Obata

Katsuaki Satoh

Junichi Nakahashi

Yoriko Yagi

Yoichi Kimura

Hikari Hashimoto

Masayuki Kozuka

Yoshihisa Fukushima

Makoto Tatebayashi

Shunji Harada

Shuji Saiki

Satoshi Takayama

Mitsuhiro Inoue

Kousaku Murata

Kazue Sato

Tsuneo Tanaka

There is provided a copying system for copying information recorded on a first recording medium onto a second recording medium. The first recording medium is recorded with copying control information for representing conditions for permitting copying of the information recorded on the first recording medium, the copying control information being multiplexed within the information recorded on the first recording medium. The copying system includes: a reading section for reading the information from the first recording medium; a detection section for detecting the copying control information within the information read from the first recording medium; a modification section for, if the copying control information represents a condition that &ldquo;only copying to a second generation copy is permitted&rdquo;, modifying the copying control information so as to prohibit any further copying; and a writing section for writing information including the modified copying control information, onto the second recording medium.

Data copying system, data copying method, data reading apparatus, data writing apparatus and data recording medium

An audio signal compression apparatus for compressively coding an input audio signal comprises a time-to-frequency transformation unit for transforming the input audio signal to a frequency domain signal; a spectrum envelope calculation unit for calculating a spectrum envelope having different resolutions for different frequencies, from the input audio signal, using a weighting function on frequency based on human auditory characteristics; a normalization unit for normalizing the frequency domain signal using the spectrum envelope to obtain a residual signal; a power normalization unit for normalizing the residual signal by the power; an auditory weighting calculation unit for calculating weighting coefficients on frequency, based on the spectrum of the input audio signal and human auditory characteristics; and a multi-stage quantization device having plural stages of vector quantizers connected in series, to which the normalized residual signal is input, and at least one of the vector quantizers quantizing the residual signal using the weighting coefficients. Therefore, a low frequency band, which is auditively important, can be analyzed with a higher frequency resolution as compared with a high frequency band, whereby efficient signal compression utilizing human auditory characteristics is realized.

Audio signal compression method, audio signal compression apparatus, speech signal compression method, speech signal compression apparatus, speech recognition method, and speech recognition apparatus

A distortion removal apparatus connected between a signal source and a signal input section of a distortion-generating system, for processing a signal output from the signal source so as to compensate for a distortion component generated in the system is provided. The distortion removal apparatus includes a frame division section for dividing a signal output from the signal source into data streams having a length of N while causing the data streams to partially overlap with one another; a Fourier transform section for performing Fourier transform of the data streams obtained by the frame division section in a time domain into a signal in a frequency domain; a memory section for storing N samples of first coefficients and N&times;N samples of second coefficients in the frequency domain. The distortion removal apparatus further includes an operation section for removing a distortion component from the output signal from the Fourier transform section by performing an operation based on the first coefficients and the output signal from the Fourier transform section and an operation based on the second coefficients and the output signal from the Fourier transform section; an inverse Fourier transform section for performing inverse Fourier transform of the output signal from the operation section into a signal in the time domain; and a frame synthesis section for sequentially connecting parts of the output signal from the inverse Fourier transform section.

Distortion removal apparatus, method for determining coefficient for the same, and processing speaker system, multi-processor, and amplifier including the same

Speech recognition method and apparatus using frequency warping of linear prediction coefficients

The apparatus of the invention calculates filter coefficients for controlling sound field and sound image, based on a plurality of first impulse response signals and a pair of second impulse response signals. The plurality of first impulse response signals indicate impulse responses from loudspeakers reproducing audio signals to both ears of a listener. The pair of second impulse response signals indicate impulse responses from a reference loudspeaker at a position at which a sound image is localized to both ears of the listener. The apparatus includes: a feature extracting section for receiving the pair of second impulse response signals, for extracting parameters representing features of the pair of second impulse response signals, and for outputting parameter signals; a signal adjusting section for adjusting at least one of the plurality of first impulse response signals based on the parameter signals, and for outputting a pair of third impulse response signals having the same features as the extracted features; and a coefficient calculating section for calculating the filter coefficients for controlling the sound field and sound image, based on the plurality of first impulse response signals and the pair of third impulse response signals applied from the signal adjusting means.

Sound field and sound image control apparatus and method

A sound quality control system according to the present invention precisely and swiftly realizes a sound quality that is desired by a listener, by controlling sound quality based on quantitative counter model between the psychological characteristic and the physical characteristic of a sound reproduction apparatus. A quantitative counter model between the physical characteristic of a sound reproduction apparatus and a plurality of the psychological quantities upon hearing a sound therefrom is constituted for each respective psychological quantity. Based on the quantitative counter model, a desired sound quality is input to a compensation characteristics extractor, and a compensation characteristic that realizes the desired sound quality is extracted. The compensation characteristic is sent to a signal processor; and an audio signal input is processed according to the compensation characteristic, and amplified to be reproduced by a loudspeaker.

Sound quality control system

A sound reproduction system for automatically conducting a tone control for an audio signal according to the present invention includes: an input terminal for inputting an audio signal; a judgment circuit for determining a ratio between a stereophonic signal component and a monophonic signal component of the input audio signal and for outputting a judgment signal; a signal processing section for receiving the input audio signal and processing the input audio signal so as to generate an output signal having uniform transmission characteristics irrespective of the listening position; an adder for receiving the input audio signal and the output signal and for adding the input audio signal with the output signal at a certain addition ratio based on the judgment signal so as to generate an added signal; and a loudspeaker for receiving the added signal and for reproducing the added signal in a plurality of positions.

Sound reproduction system and a sound reproduction method

A sound signal picked-up by a microphone is processed in a howl suppresser including a digital filter. A frequency analyzer performs frequency analysis of the picked-up sound signal. A howl detector detects a howl contained in the sound signal from a result of frequency analysis by the frequency analyzer. A coefficient calculator calculates coefficients to be input to the digital filter to suppress the howl according to a detection result by the howl detector, and a controller inputs the calculated coefficients to the digital filter. The howl detector judges that a maximum peak power level among power levels of the sound signal in a frequency region analyzed by the frequency analyzer is a howl component when a ratio of the maximum peak power level to a mean power level of the sound signal is larger than a predetermined threshold level, preferably for a predetermined threshold time. Also, a threshold controller is provided for controlling the threshold level and/or the threshold time so as to enhance the accuracy of the howl detection.

Sound amplifying apparatus with automatic howl-suppressing function

A sound field controller for generating apparent sound sources by adjusting the amplitude and delay time of a sound signal so that the sound will be perceived by plural listeners as sound coming from a location separated from the specific location of the front speakers, and for additionally controlling the effect of the apparent sound sources by evaluating the attributes of the source sound signal. The controller includes FIR filters for generating a left sound pattern signal, FIR filters for generating a right sound pattern signal, a first delay circuit for delaying the left and right sound pattern signals by a first predetermined time and applying the delayed left and right sound pattern signals to the left and right speakers, respectively, to introduce an apparent sound source located left rear of a center listener; and a second delay circuit for delaying the left and right sound pattern signals by a second predetermined time and applying the delayed left and right sound pattern signals to the right and left speakers, respectively, to introduce an apparent sound source located right rear of a center listener.

Sound field controller

A music/voice discriminating apparatus is composed of a signal processing portion for effecting the signal processing upon input acoustic signals, a music/voice deciding portion for discriminating whether the input acoustic signals are music or voice, a first signal processing portion for optimally setting acoustic parameters for the signal processing respectively for music or voice, and a second signal processing portion for controlling the acoustic parameters of the first signal processing portion in accordance with the decision results of the music/voice deciding portion so that it may become a desirable value set in the second parameter setting portion.

Music/voice discriminating apparatus

A sound field is generated responsive to direct sound picked up by a direct-sound collecting microphone and indirect-sound picked up by an indirect-sound collecting microphone. Respective processing circuits are provided for signal processing the sound signals of the direct-sound collecting microphone and the indirect-sound collecting microphone. An adaptive filter is provided having a transfer function equal to a transfer function from a reproducing speaker to the indirect-sound collecting microphone. The output of the signal processing circuit associated with the indirect-sound collecting microphone is filtered by the adaptive filter, and the output of the adaptive filter is subtracted from the output of the indirect-sound collecting microphone. The output of the subtractor is then applied to the signal processing circuit associated with the indirect-sound collecting microphone for signal processing. The transfer function is initially set in the adaptive filter by applying an output of a signal generator thereto.

Sound field variable apparatus

Control codes for controlling processing of an audio signal by a sound field variation circuit to produce desired sound fields are recorded on a monaural track of a video tape concurrent with recording of video and audio signals, and can thereby be subsequently played back for producing sound fields which are respectively synchronized with video images.

Apparatus for supplying control codes to sound field reproduction

A reflection sound compression apparatus extracts and compresses, most appropriately with a physical evaluation value, an impulse response of a hall, etc. which is obtained by calculation and actual experiments to reflection sounds in a number required by a sound field controller by using a learning identification method.

Reflection sound compression apparatus

In the process of forming the effect sound for reproducing a sound field, a down-sampling part for reducing the sampling frequency of the digital signal is disposed before the step of the digital operation which becomes the central part of the forming process, by which a large amount of operation processing is carried out at a low sampling rate. With respect to the direct sound, processing such as gain adjustment is carried out without decreasing the sampling frequency. This results in a sound field control system which permits one to realize a higher quality and natural sound field control effect without significantly increasing the amount of hardware needed.

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Nishinomiya, Japan

Mitsuhiko Serikawa