Segmental level analysis of laryngeal function in persons with motor speech disorders

Laryngeal behavior for segmental function is often disturbed in motor speech disorders. Loss of voicing contrasts has been shown to significantly contribute to speech intelligibility deficits. The present study was designed to examine two commonly erred laryngeal contrasts, the word-initial voiced-voiceless and glottal-null contrasts using acoustic analysis techniques. Acoustic measures were compared to expectations for the contrast based on data in the literature as well as listeners' perception of the token. Findings indicate a mismatch between acoustic data and both expectations for the contrasts and listener perception. There is some indication that changes in laryngeal segmental function are related to aging in general and may be exaggerated in persons with motor speech disorders.