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6091773 Data compression method and apparatus  
A method and apparatus for measuring the "perceptual distance" between an approximate, reconstructed representation of a sensory signal (such as an audio or video signal) and the original sensory...
6092039 Symbiotic automatic speech recognition and vocoder  
The device and method of the invention receives a digital speech signal, which is processed by an Acoustic Processor to produce a Mel-Cepstrum Vector and Pitch. This is recalibrated and encoded....
6078881 Speech encoding and decoding method and speech encoding and decoding apparatus  
Speech encoding using searching of a code book for a code that matches an input speech signal, and speech decoding using the code book are disclosed. A random series of code samples is stored in a...
6070136 Matrix quantization with vector quantization error compensation for robust speech recognition  
A speech recognition system utilizes both matrix and vector quantizers as front ends to a second stage speech classifier. Matrix quantization exploits input signal information in both frequency...
6067515 Split matrix quantization with split vector quantization error compensation and selective enhanced processing for robust speech recognition  
A speech recognition system utilizes both split matrix and split vector quantizers as front ends to a second stage speech classifier such as hidden Markov models (HMMs) to, for example,...
6061648 Speech coding apparatus and speech decoding apparatus  
In a speech coding apparatus, an input device inputs a mixed speech signal of a plurality of speakers. A separating device analyzes period characteristics of the input mixed speech signal, and...
6055496 Vector quantization in celp speech coder  
A process for generation of codevectors in the production of synthetic speech in a communication system employing code-excited linear prediction (CELP) is implemented by dividing frames of sampled...
6044343 Adaptive speech recognition with selective input data to a speech classifier  
One embodiment of a speech recognition system is organized with speech input signal preprocessing and feature extraction followed by a fuzzy matrix quantizer (FMQ) designed with respective...
6023672 Speech coder  
An excitation quantizer 60 in a speech encoder includes a divider, which divides M pulses representing in combination a speech signal into groups each of L pulses, L being smaller than M. The...
6016469 Process for the vector quantization of low bit rate vocoders  
A process for the vector quantization of low bit rate vocoders, including determining a coding region by surrounding with an envelope a scatter of points of an autocorrelation matrix of reflection...
6014623 Method of encoding synthetic speech  
A method of synthetic speech, wherein the method forms a speech data base, the speech data base includes plural syllables, each of the syllables having a total frame number of the syllable and...
6009387 System and method of compression/decompressing a speech signal by using split vector quantization and scalar quantization  
Apparatus for processing acoustic features extracted from a sample of speech data forming a feature vector signal every frame period includes a first linear prediction analyzer, a vector...
6009384 Method for coding human speech by joining source frames and an apparatus for reproducing human speech so coded  
For coding human speech for subsequent audio reproduction thereof, a plurality of speech segments is derived from speech received, and systematically stored in a data base for later concatenated...
6009391 Line spectral frequencies and energy features in a robust signal recognition system  
One embodiment of a speech recognition system is organized with speech input signal preprocessing and feature extraction followed by a fuzzy matrix quantizer (FMQ). Frames of the speech input...
6006177 Apparatus for transmitting synthesized speech with high quality at a low bit rate  
The invention provides a speech coding apparatus wherein a perceptual weighting filter is realized with a comparatively small amount of calculation. The speech coding apparatus includes a...
6006178 Speech encoder capable of substantially increasing a codebook size without increasing the number of transmitted bits  
In a speech encoder, a gain codebook switching circuit is supplied with short-term prediction gains from a short-term prediction gain calculator circuit and with mode information through an input...
6006179 Audio codec using adaptive sparse vector quantization with subband vector classification  
An audio coder/decoder ("codec") that is suitable for real-time applications due to reduced computational complexity, and a novel adaptive sparse vector quantization (ASVQ) scheme and algorithms...
5999899 Low bit rate audio coder and decoder operating in a transform domain using vector quantization  
Audio source data is subjected to a pre-emphasis step (302) to perform gross decorrelation, followed by an adaptive linear prediction (306) to perform further decorrelation. A transform is...
5978758 Vector quantizer with first quantization using input and base vectors and second quantization using input vector and first quantization output  
A first vector quantizer generates output codevectors corresponding in number to a number determined by a predetermined number of bits through linear coupling of integer coefficients of a...
5974378 Multi-stage vector quantization with efficient codebook search  
A method of using a computer (11) to perform a multi-stage vector quantization process (13a). At each stage of the process (13a) subsequent to the first stage, input vectors from the previous...
5970444 Speech coding method  
An ACELP speech coding method according to ITU-T Recommendation G.729. When coding a random component vector, each of random component vector forming together the random codebook is formed of...
5970443 Audio encoding and decoding system realizing vector quantization using code book in communication system  
An audio encoding-decoding system is constructed between a transmitting station and a receiving station which are connected together through communication lines. The transmitting station...
5966688 Speech mode based multi-stage vector quantizer  
A speech mode based multi-stage vector quantizer is disclosed which quantizes and encodes line spectral frequency (LSF) vectors that were obtained by transforming the short-term predictor filter...
5963896 Speech coder including an excitation quantizer for retrieving positions of amplitude pulses using spectral parameters and different gains for groups of the pulses  
In a speech coder, an excitation quantizer 360 retrieves the positions of M non-zero amplitude pulses, which together constitute an excitation, by using spectral parameters and with a different...
5960390 Coding method for using multi channel audio signals  
There is provided a coding method which can effectively prevent a pre-echo and a post-echo from being generated and can perform effective coding to which an psycho-acoustic model is applied. A...
5946651 Speech synthesizer employing post-processing for enhancing the quality of the synthesized speech  
A post-processor 317 and method substantially for enhancing synthesised speech is disclosed. The post-processor 317 operates on a signal ex(n) derived from an excitation generator 211 typically...
5943647 Speech recognition based on HMMs  
A speech recognition method that combines HMMs and vector quantization to model the speech signal and adds spectral derivative information in the speech parameters. Each state of a HMM is modeled...
5943644 Speech compression coding with discrete cosine transformation of stochastic elements  
A digital speech waveform is divided into frames and sub-frames. Spectrum envelope information, pitch elements and stochastic elements are extracted and coded for the frames and sub-frames. A...
5930748 Speaker identification system and method  
A speaker identification system (10) employs a supervised training process (100) that uses row action projection (RAP) to generate speaker model data for a set of speakers. The training process...
5924062 ACLEP codec with modified autocorrelation matrix storage and search  
A codebook correlation matrix comprises a Toeplitz-type (diagonally symmetric) matrix which is calculated from a forty sample subframe of a speech signal, forming a 40×40 matrix. The resulting...
5924065 Environmently compensated speech processing  
In a computerized method for processing speech signals, first vectors representing clean speech signals are stored in a vector codebook. Second vectors are determined from dirty speech signals....
5920853 Signal compression using index mapping technique for the sharing of quantization tables  
A signal compression system includes a coder and a decoder. The coder includes an extract unit for extracting an input feature vector from an input signal, a coder memory unit for storing a...
5920833 Audio decoder employing method and apparatus for soft-muting a compressed audio signal  
An MPEG audio decoder includes a Vector FIFO buffer and a windowed polyphase filter. Groups of vector samples are zeroed out prior to storage in the Vector FIFO buffer when it is desired to...
5918205 Audio decoder employing error concealment technique  
An MPEG audio decoder includes a Vector FIFO buffer and a windowed polyphase filter. Groups of vector samples are zeroed out prior to storage (or after storage, if desired) in the Vector FIFO...
5909663 Speech decoding method and apparatus for selecting random noise codevectors as excitation signals for an unvoiced speech frame  
If the same parameter is repeatedly used in an unvoiced frame inherently devoid of pitch, there is produced a pitch of the frame length period, thus producing an extraneous feeling. This can be...
5899967 Speech decoding device to update the synthesis postfilter and prefilter during unvoiced speech or noise  
In the disclosed speech decoding device, activation of a postfilter process is halted during unvoiced sections. However, the updating process of the internal states of the postfilter continues...
5897615 Speech packet transmission system  
A speech packet transmission system of the present invention has a speech coding device and a speech decoding device. In the coding device a speech coder (21) codes a PCM (Pulse Code Modulation)...
5890110 Variable dimension vector quantization  
A variable dimension vector quantization method that uses a single "universal" codebook. The method can be given the interpretation of sampling full-dimensioned codevectors in the universal...
5873060 Signal coder for wide-band signals  
Wide-band speech signals and also music signals are coded with relatively less computational efforts and less sound quality deterioration even at low bit rates. A spectral parameter calculator...
5867814 Speech coder that utilizes correlation maximization to achieve fast excitation coding, and associated coding method  
A speech coder, formed with a digital speech encoder and a digital speech decoder, utilizes fast excitation coding to reduce the computation power needed for compressing digital samples of an...
5832180 Determination of gain for pitch period in coding of speech signal  
A speech signal coding apparatus includes a dividing section for dividing a speech signal in units of sub-frames. A spectrum parameter section calculates a spectrum parameter for each sub-frame....
5828996 Apparatus and method for encoding/decoding a speech signal using adaptively changing codebook vectors  
An encoding apparatus in which an input speech signal is divided into blocks and encoded in units of blocks. The encoding apparatus includes an encoding unit for performing CELP encoding having a...
5826225 Method and apparatus for improving vector quantization performance  
A method and apparatus for providing high-speed data compressing without sacrificing the quality of data reconstruction. Each input vector or block of original data is expressed as a combination...
5826224 Method of storing reflection coeffients in a vector quantizer for a speech coder to provide reduced storage requirements  
An input speech signal is encoded as one or more reflection coefficients. To reduce storage requirements, the reflection coefficients are scalar quantized by storing an N-bit code rather than the...
5826226 Speech coding apparatus having amplitude information set to correspond with position information  
The invention provides a speech coding apparatus by which a good sound quality can be obtained even when the bit rate is low. The speech coding apparatus includes an excitation quantization...
5822722 Wide-band signal encoder  
A block length judging circuit 120 switches block lengths based on a feature quantity obtained from an input signal. A transform circuit 200 executes transform of the signal into frequency...
5822723 Encoding and decoding method for linear predictive coding (LPC) coefficient  
A speech signal encoding/decoding method is provided. The method of encoding LPC coefficients includes dividing the nth-order line spectral frequencies into lower, middle and upper code vectors,...
5819213 Speech encoding and decoding with pitch filter range unrestricted by codebook range and preselecting, then increasing, search candidates from linear overlap codebooks  
A speech encoding method and apparatus including analyzing, using a codebook expressing speech parameters within a predetermined search range, an input speech signal in an audibility weighting...
5819212 Voice encoding method and apparatus using modified discrete cosine transform  
A method and apparatus for encoding an input signal, such as a broad-range speech signal, in which a number of decoding operations with different bit rates are enabled for assuring a high encoding...
5819224 Split matrix quantization  
A speech synthesis system in which coefficients of a speech synthesis filter are quantized. An LSP or other filter coefficient representation which evolves slowly with time is generated for each...