Vocal fold contact area patterns in normal speakers: an investigation using the electrolaryngograph interface system.

This study investigates patterns of vocal fold movement in normal speakers. With the use of new computer software, laryngograph (Lx) waveforms from 100 normal speakers were examined. Specifically, four phases of the Lx waveform were observed and measured. These were then compared on both an interpersonal and intrapersonal basis. The results indicated that four phases were clearly identifiable in almost all subjects and that measurements of the closure and closed phases showed a high degree of consistency. The opening and open phases were more variable. In addition the onset and offset patterns of phonation were observed. Clear patterns were identified, consistent between speakers. The results are discussed with reference to the degree of consistency that can be expected in the vocal fold movement of normal speakers.