Showing papers on "Spectrogram published in 1970"

System for automatic formant analysis of voiced speech.

Abstract: A system for automatically estimating the lowest three formants and the pitch period of voiced speech is presented. The system is based on a digital computation of the cepstrum (defined as the inverse transform of the log magnitude of the z‐transform). The pitch period estimate and smoothed log magnitude are obtained from the cepstrum. Formants are estimated from the smoothed spectral envelope using constraints on formant frequency ranges and relative levels of spectral peaks at the formant frequencies. These constraints allow the detection of cases where two formants are too close together in frequency to be resolved in the initial spectral envelope. In these cases, a new spectral analysis algorithm (the chirp z‐transform algorithm) allows the efficient computation of a narrow‐band spectrum in which the formant resolution is enhanced. Formant and pitch period data obtained by the analysis system are used to control a digital formant synthesizer. Results, in the form of spectrograms, are presented to illu...

Speech spectrograms using the fast Fourier transform

Abstract: An important aid in the analysis and display of speech is the sound spectrogram, which represents a time-frequency?intensity display of the short-time spectrum.1-3 With many modern speech facilities centering around small or medium-size computers, it is often useful to generate spectrograms digitally, online. The fast Fourier transform algorithm provides a mechanism for implementing this efficiently.

Toward Objective Phonetic Transcription - An On-Line Interactive Technique for Machine-Processed Speech Data

Abstract: The derivation of phonetic transcription is one component of speech processing that can utilize man-data techniques. This involves the assignment and time location of phonetic symbols to speech data. Conventional transcription methods are suspect in at least two respects. First, the symbols assigned are often based on "talker intention," or what "should be," rather than on physical evidence; and, second, symbol location is usually related to subsequent machine processing only minimally. An exploratory procedure is described that operates on-line, in an interactive mode, utilizing a graphic display with an IBM System/360 model 40. Available for display are a digital sound spectrogram, the power spectrum at a given time sample, an average spectrum for a given sound class, and correlations of a current spectrum with average spectra. Using this technique, location and assignment of phonetic symbols are less dependent upon operator expertise (and/or bias) and highly related to subsequent processing.

Speech synthesis from a spectrographic trace

Abstract: A voice synthesis system using a sound spectrogram, showing the spectrum in the form of a plot of frequency against time with intensity being represented by the variable density of the plot. The spectrogram is scanned and analog signals are produced the amplitude of which is a function of the density of the spectrogram plot. Synchronously with the production of the analog signals oscillation signals are produced at the respective scanning frequencies and are amplitude modulated by the analog signal. The amplitude modulated oscillation signals are stored and summed and subsequently reproduced thereby synthesizing an acoustic signal.

Acoustical Manifestations of Emotional Speech

Abstract: High‐quality tape recordings were obtained of professional method actors reading the dialogue of a short scenario especially written for determining those parameters in the speech signal that reflect a speaker's emotions. Excerpts from the recordings were subjected to both quantitative and qualitative analyses. Several acoustical manifestations were noted for the various emotions portrayed by the actors. Some of these acoustical correlates are measurable quantities that are amenable to extraction from the speech signal by automatic means; others represent characteristics of patterns that can be observed and categorized by visual examination of sound spectrograms. Some of the quantitative results found support the results of previous studies. Other findings, particularly those describing qualitative effects observed on spectrographic patterns, have not been reported previously.

Subjective assessment of computer-simulated telephone calling signals

Abstract: An experimental family of tones intended as telephone calling signals was generated by computer simulation. The synthesis technique allowed systematic manipulation of the parameters of the tones. Selected results of the computations were submitted to listeners for evaluative judgments. The evaluative data were analyzed by a multidimensional method that reveals the perceptual dimensions on which listeners' opinions differ. The dimensions thus defined were interpreted in terms of the parameters of the synthesis.

Spectrographic Errors in Pulsed Discharges

Abstract: The method of electronically processing the detector signal can be critical when making spectrographic measurements on a pulsed discharge. The output of the commonly used synchronous detector is dependent on both signal amplitude and signal pulse shape, and, when the shape of the radiated light pulse varies with wavelength, serious errors can be introduced. Two disparate spectrograms are shown that were taken from the same light source, differing only in signal processing, and the reasons for the discrepancies are explained. When taking spectrograms of pulsed light sources where afterglow effects may result in a variable pulse shape, it is recommended that the synchronous detector not be used; if the resultant spectrogram is to be power vs wavelength, then some form of signal sampling should be used instead. A measurement technique using a sampling oscilloscope for signal processing is described. A curve is included that predicts the magnitude of error introduced when using the synchronous detector to pro...