Abstract: Speech information communicating method and apparatus for transmitting speech information through a transmission system having a low bit rate transmission capacity such as Telex to a receiver station for reproduction. The apparatus comprises at the side of transmitter station a speech recognition device for extracting by high data compression a character train corresponding to syllable units or phonetic symbol from an input speech and simultaneously determining accent types of words or phrases contained in a character train, and a code converter for encoding the extracted character train and the identified accent type in the form of Telex code, unoccupied Telex codes being allotted to the accent type codes and for producing an encoded speech information signal including a time series of character codes having the accent type identifying codes inserted therein.

Abstract: A method of zero-level adjustment of a rate sensor wherein the zero-level adjustment in the detection of yawing rate is obtained by subtracting a quantity of drift of an output from the rate sensor during the period of time that the vehicle is stopped or standing still from a subsequent output therefrom in the normal travelling operation of the vehicle. The current state of the vehicle, i.e., whether it is travelling or standing still, is detected by a travel distance sensing device which generates electric pulse signals for a given unit distance travelled by the vehicle; and the sampled outputs from the rate sensor are averaged for the period from immediately after the detection of a standing still state of the vehicle to the moment just before a starting of travel thereof. The thus-obtained averaged value is determined as a current drifting value of the sensor and is subtracted from a current angle of deviation value obtained during normal travel of the vehicle.

Abstract: Speech sound recognition is made using a reduced number of speech parameter elements, e.g., five correlation coefficients rather than sixteen spectral coefficients. The five correlation coefficients are derived from comparison of the spectral coefficients of unknown or standard sounds against the spectral coefficients of five highly-separable vowel-like sounds. Then, unknown-sound correlation coefficients are compared with standard-sound coefficients for recognition.

Abstract: Speech signal presence is decided if total signal power is above a first threshold, and if either low or high frequency components exceed thresholds as a large fraction of the total power. Total power is calculated as the zero-order auto-correlation coefficient, and fractional power of frequency components is calculated as the first-order partial auto-correlation coefficient.

Abstract: A speech pitch period extracting apparatus includes an amplitude classifying and coding circuit for classifying and coding the amplitude of a selected frame of a speech waveform signal to be analyzed into at least three levels of coded data, and a coincidence circuit for detecting the number of coincidences which occur between sets of coded data signals from said selected frame separated by different arbitrary time intervals, thereby to determine that time interval for which the maximum number of code coincidences between data signals occurs and to identify that time interval as the pitch period of the speech waveform signal. In addition, there may be provided a circuit for normalizing the speech waveform signal included in the frame to be analyzed, in accordance with the maximum peak value of the speech waveform, the speech waveform signal after being normalized is applied to the classifying and coding circuit.

Abstract: A multi-frequency signal receiver, in which the digital input signals having the sampling frequency of 8 KHz or a multiple thereof are resampled at a sampling frequency of 4 KHz by means of a resampling circuit and in which the signals thus resampled are subjected to the band selection by means of a digital filter so that the frequency of the input signals may be identified.

Abstract: Computation of the partial correlation coefficients (PARCOR K.sub.i) of a signal, using less cascaded hardware, is implemented by first deriving a sequence of auto-correlation coefficients (v.sub.j) which are then transformed into a sequence of K.sub.i using a single section digital filter plus recirculating circuitry for data iteration.

Abstract: Signal-to-noise is enhanced by including the upper sideband of a sampled-speech signal with the original baseband signal for further signal processing. The invention features shifting both bands to form a continuum from 0 Hz to the sampling frequency. Application in a speech recognition is shown.

Abstract: A pre-processing system for a speech recognition system nullifies the distortion in a received signal caused by the transmission line by forming a normalized received signal whereby the distortion is cancelled: the received signal is spectrally averaged to form a mean spectrum which is used to adjust a filter to a characteristic inverse to the distortion; this filter then filters the received signal to form the normalized received signal s.sub.j '(.omega.,t)=S.sub.j (.omega.,t)/S.sub.j (.omega.) which is equal to the normalized source signal =S.sub.i (.omega.,t)/S.sub.i (.omega.).

Abstract: A multifrequency signal receiving system comprising a filter for whitening a received signal, a correlator for extracting partial autocorrelation coefficients from the output of the whitening filter, a prediction error analyzer for judging the presence or absence of the multifrequency signal by analyzing prediction analysis errors from the output of the whitening filter, and a control unit responsive to the output of the analyzer indicative of the presence of the multifrequency signal for determining the frequency included in the received signal using the partial autocorrelation coefficients thereby identifying that the received signal is the multifrequency signal.

Abstract: Improvements in a push button signal receiving device for use in a voice response system, wherein in order to permit a push button signal from a user's telephone terminal to be received even during the period when a responding voice signal is being transmitted through the system, an analyzer for the parameter analysis of the responding voice signal and an inverse filter responsive to the analyzer for flattening the spectrum of the responding voice signal which is mixed into the push button signal are provided, whereby the influence of the responding voice signal mixing into the signal to be applied to a push button signal detector is erased, and the push button signal, which may be feeble in comparison to the responding voice signal, is detected and recognized nevertheless.