Initial validation of an indirect measure of subglottal pressure during vowels.

Some methods for direct measurement of subglottal pressure during speech are invasive and thus cannot be used on a routine basis. The development of noninvasive techniques is thus desirable, and a simple indirect method for measuring subglottal pressure from records of oral pressure during consonants has recently been proposed and applied to studies of glottal resistance during phonation. In order to bae useful, indirect measurement procedures should be validated by comparisons with direct measurements, and the present experiment was designed for such a comparison. Miniature pressure transducers were used to obtain records of pressure below and above the glottis. Results showed nonsignificant differences and a high correlation between the direct and indirect measurements. This indirect method for measuring subglottal pressure thus appears to provide valid results.