ABSTRACT
1. In the present study we measured intraoral air pressure (Po) during the production of the stop consonant/p/, in a syllabic contes, in normal and surgically repaired cleft palate subjects. po was measured by placing a sensing catheter between the lips in the oral cavity. The catheter was connected to a pressure transducer and the output signals were amplified and transmitted to a recorder. 2. When compared to normal individuals, cleft patients with velopharyngeal insufficiency (VPI) and oral articulation for/p/presented significantly lower Po levels (P<0.01) but pressure curves of normal shape. 3. In cleft palate patients with VPI and glottal coarticulation for/p/, Po was absent or markedly reduced; in the latter case, the Po curve was of a characteristically irregular shape. 4. These results suggest thata measurement of Po during the production of a selected consonant appears to be a suitable instrumental method for identifying VPI and discrininating an oral stop from the compensatory glottal stop often observed in postoperative cleft palate speakers