A preliminary investigation of phonetic diversity in adults with motor speech disorder

Abstract

A preliminary investigation of the phonetic diversity characterizing the speech of non-impaired and speech-impaired adults was performed. Two measures of phonetic diversity, the ratio of consonants-to-vowels (C:V) and the phonetic product (PP), were applied to the spontaneous speech productions of a group of non-impaired adult females and adult females with a motor speech disorder. The C:V ratio evaluates the ratio of supraglottal-to-glottal articulations occurring within a conversational speech sample. The PP evaluates the frequency of occurrence of consonant and vowel sounds within an utterance according to place of articulation categories. Significant differences in C:V ratio were found between the two groups; however, the PP failed to discriminate the groups. Results are discussed with regard to the general articulatory characteristics of non-impaired and speech-impaired adults, as well as the usefulness of examining phonetic diversity in adults with motor speech disorders.