Vocal Intensity, Subglottic Pressure and Air Flow Relationships in Singers

Abstract

The effects of variations in fundamental frequencies (vocal pitch) and sound intensities (volume, loudness) on transglottic air flow and sub-glottic air pressure were studied in singers. Glottal resistance is far more important in supporting a tone of increasing loudness than air flow, and subglottic pressure measurements do not necessarily reflect sound pressure levels. Poor vocal technique exerts a markedly disturbing effect on flow-pressure relationships. Inadequate breath support impairs vocal quality by causing secondary interfering glottal tensions, and intraesophageal pressure is not a reliable indicator of subglottic pressure.