Air flow and intelligibility of speech of normal speakers and speakers with a prosthodontically repaired cleft palate

In recent years there has been an increase in the use of physiologic tests for the analysis of air flow and pressure required for speech production. Qualitative and quantitative evaluations of these aspects have been made in subjects with normal and defective speech. 1-4 Various methods have been used to determine velopharyngeal function. The techniques that have been used in diagnosis and management have included radiography, air flow and pressure measurements, and use of the trained ear of the speech pathologist. In 1965 Skoog 5 stated that conclusions concerning the velopharyngeal system were even then based on inadequate information. This may have been due to a lack of means for objective study of the structures involved with the velopharyngeal mechanism during connected speech. Objective records using respirometric techniques for air flow and pressure measurements have been used and correlated with listener perception of speech intelligibility. A phenomenon termed hypernasality, generally exhibited in the speech of cleft-palate patients, may contribute to listeners' judgments of unintelligible speech. It cannot be assumed, however, that hypernasality is either the greatest or the sole contributor to reduced intelligibility. As Moll 6 reported, "... speech dimensions must be defined ultimately in terms of listener perception, nasal voice quality is defined best as a perceptual dimension." The fact that air may be inappropriately directed into the nasal cavity with or without a judgment of hypernasality could contribute to listener perception of unintelligible speech. Inappropriate air direction, resulting from velar insufficiency, may establish the relationship between ~ *Associate Professor. Communication Disorders Program. **Associate Professor, Speech and Hearing Clinic. air flow and perception of intelligibility, an important factor in the speech process. By establishing the relationship between air flow and perception of intelligibility, a check-and-balance system can be developed to provide more comprehensive rehabilitation for cleft-palate speakers. This study was designed to assess the relationship between air flow and listeners' identification of certain fricatives in selected words for normal and cleft-palate speakers. METHOD