Impact of phonatory frequency and intensity on glottal area waveform measurements derived from high-speed videoendoscopy

Abstract

Measurements of glottal area waveform from high-speed videoendoscopy were made on vocally healthy females (n = 41) and males (n = 25) during sustained /i/ production at typical pitch and loudness, high pitch, and soft phonation. Three trials of each condition were performed yielding 594 samples. Statistical analysis of glottal cycle quotients (open quotient (OQ), speed quotient (SQ), rate quotient (RQ), glottal gap index (GGI)), glottal cycle periodicity (amplitude, time (TP)), glottal cycle symmetry (phase asymmetry index, spatial symmetry index, and amplitude symmetry index), glottal area derivative (maximum area declination rate (MADR)), and mechanical stress measures (stiffness index (SI), amplitude-to-length ratio (ALR)) revealed that only SI varied systematically across pitch and loudness conditions for males and females. Variations in pitch and loudness results in changes in SI, ALR, RQ, MADR, and SQ for females, whereas variations in target pitch and loudness results in changes in SI, ALR, RQ, MADR, GGI, OQ, and TP for male speakers. Carefully selecting the laryngeal parameters derived from high-speed videoendoscopy has the potential to provide insights clinically into the known laryngeal biomechanics expected for the increase in pitch and reduction in vocal loudness.