The acoustic analysis of speech disorders in an apraxia of speech patient
—fluctuation of speech length, maximal sound pressure of the initial consonant and the fundamental frequency—

Abstract

    The purpose of this study was to analyze the perturbation of speech disorders by acoustic analysis. We compared the speech of an apraxia of speech patient with those of 5 normal controls regarding speech length, maximal sound pressure of the initial consonant and the fundamental frequency. Thirty words of 2 to 4 syllables were spoken 3 continuous times. Fluctuations of speech length, maximal sound pressure of the initial consonant and the fundamental frequency in 1 vowel were inconsistent in the apraxia of speech patient, while those of the control subjects were consistent. However, the fundamental frequency in words was flat in the apraxic patient compared to the control subjects. These findings suggest that the speech abnormalities in apraxia of speech patients are caused by a disorder of the intentional movement in articulation organs including the co-ordination disorder in expiration and/or glottal closure. Acoustic analysis is useful to examine auditory symptoms in detail.