Severity of Nasality in Three Selected Speech Tasks

Abstract

This study was designed to evaluate the relative effects of three speech tasks upon the perception of nasality for 10 nasal speakers without cleft palate (Group I) and 10 nasal speakers with cleft palate (Group II). The three speech tasks consisted of the production of (a) five isolated vowels, (b) the same five vowels in consonant-vowel-consonant (CVC) syllables, and (c) the same five CVC syllables in a connected speech passage. The psychological scaling procedure of equal-appearing intervals was used to assess the severity of nasality. The results indicate that for both groups of nasal speakers, CVC syllables removed from a connected speech passage are judged to be less nasal than either isolated vowels or isolated CVC syllables. For nasal speakers with cleft palate, the relationships of nasality in a connected speech passage to nasality in each of five vowels produced in isolation, to each of five CVC syllables produced in isolation, and to each of the same five CVC syllables produced in a connected speech passage are low. These same relationships do not, in general, exist for nasal speakers without cleft palate.