J F Lubker | Search PubMed

PubMed1977

An acoustic-perceptual method for the quantitative evaluation of hypernasality.

A computer implementation is proposed as a method for assessing the quality of an individual's speech from a perceptual and communicative point of view. The input to this procedure is a standardized set of speech samples (vowels and selected consonants) designed to permit an evaluation of the speaker's phonology. The output is a numerical specification of the functional adequacy of the target values of the phonetic segments under analysis. The computer program consists of three parts: a simulated auditory analyzer, the output of which is a spectral representation of each test item; an algorithm that computes a psychoacoustically based measure of distinctiveness or perceptual distance for each pair of test spectra, and a routine for comparing, in terms of this measure, the test items with the corresponding reference items drawn from a population of normal speakers or a recording made before patient intervention.

Acoustics↗

PubMed1975

Normal velopharyngeal function in speech.

What has been presented in the foregoing pages is the broad outline of a theory of velopharyngeal function in normal speech production. It is suggested that the velopharyngeal musculature functions in a predictably variable manner to provide predictably variable structural movements and positioning. The variability is predictable, based on the phenomenon of coarticulation, given knowledge of where the structures are, where they must go to produce a perceptually acceptable phonime, and where they must subsequently be for later phonemes. The theory is not complete, as will be discussed below. Nevertheless, it demonstrates the complexity of velopharyngeal function. Many variables are involved simultaneously in the movements of this mechanism, and it is not enough to consider a muscle, a structure, or a phoneme. The action of any muscle is influenced by the action of others in the system, the movements of any structure are influenced by movements of other structures, and any phoneme is influenced-sometimes heavily so-by phonemes around it. Thus, the central nervous system programming of oralization and nasalization gestures must be a complicated process. Certainly, the results of that programming are complicated.

Electromyography↗