A pilot study of SPINE test scores and measures of tongue deviancy in speakers with severe-to-profound hearing loss.

Two developments show promise in the assessment and remediation of defective speech production in persons with hearing loss. A perceptual speech-intelligibility test, the SPINE (for Speech Intelligibility Evaluation), is a simple, clinician-administered instrument which is valid, reliable, and clinically efficient. In addition, the development of acoustic measures of tongue deviancy, computed from formant frequencies, makes possible a direct lateral visualization of tongue placement in relation to standard vowel placement. In this study, SPINE test scores of 28 persons with severe-to-profound hearing loss were correlated with two measures of tongue deviancy during production of the vowels /i/, /a/, and /u/. For both measures of tongue deviancy, correlations with the SPINE were significant for the three vowels combined and for the isolated vowel /i/. These findings suggest that clinicians may ultimately have two different but complementary means of assessing speech production in persons with hearing loss.

A noninvasive acoustic method using frequency perturbations and computer-generated vocal-tract shapes.

This study investigated improved processing of acoustic data with two adult Down's syndrome subjects. Sustained vowel samples were processed through a fast-Fourier-transform spectrum analyzer, and digital waveform data were used to obtain period-by-period measurements of the fundamental frequencies. Unusual frequency perturbation (jitter), later identified as diplophonia, was found for one of the Down's subjects. In addition, the first three formant frequencies of the vowels were determined and, utilizing an algorithm described by Ladefoged and his colleagues, computer-generated vocal-tract shapes were plotted. Differences in vocal-tract shapes, especially for the back vowels, were observed between the Down's female and the normal shape. Correlations between vocal-tract shapes of the Down's subjects and those for a normal man or woman were computed. A partial three-way factor analysis was carried out to determine those load factors or coefficients for each subject that were due to individual differences. These procedures, offering synthesized techniques portraying the interpharyngeal/oral functioning of the speech structures, may eventually have direct noninvasive diagnostic and therapeutic benefit for voice/resonance-disordered clients.