Direct Comparison of Subglottal and Esophageal Pressure during Speech

Abstract

Subglottal air pressure during speech was measured by two methods: (1) by recording from a tracheal catheter, and (2) by recording from a 10-cm-long balloon positioned in the middle third of the esophagus and correcting for the pressure developed by the elastic recoil of the lungs. A simple linear elastic-recoil correction factor was devised. The two measures of subglottal air pressure yielded similar results. Some of the conditions that can produce pressure artifacts in esophageal balloons are discussed. The data also show that peaks in subglottal air pressure are not always associated with phonetic prominence, particularly when several noncontiguous words are emphasized in the same breath group.