Oral Port Constriction, Nasal Resistance, and Respiratory Aspects of Cleft Palate Speech: An Analog Study

  • Donald W. Warren
  • William E. Ryon

Abstract

Recent studies of 'cleft palate speech' have indicated that measures of velopharyngeal function alone are not adequate to account for the articu-latory errors which are observed (2, 3, 5, 10). These studies suggest that the role of oral and nasal structures should be investigated, since com— pensatory mechanisms may be responsible for consonant deficits. It is not possible, however, with present technology to explore these complex structures in sufficient detail in the human. In this study, therefore, the effects of the oral and nasal structures on pressure and airflow associated with con— sonant production were investigated, using a simple mechanical model instead. The rationale for using an analog of the upper speech mechanism was presented in an earlier report (10). Briefly, justification is based on the assumption that simple hydraulic laws apply to the respiratory aspects of speech. Method The apparatus (see Figure 1) has been described previously (7—10). A polyethylene catheter is used to transmit pressure within the oropharynx to a differential pressure transducer. Flow rate is measured by a pneumo-tachograph attached to the model nose. The air source for these experiments is provided by a respiratory pump which produced airflow in the form of half sine waves. A four—channel magnetic tape recorder is used to record the pressure—flow data which are later replayed into a dual—channel cathode ray oscillograph recording camera. Calibration of the pneumotachograph is accomplished with a rotameter and pressure is calibrated against a water manometer.
Published
1967-01-01
Section
Articles