Characteristics of speech production after tracheoesophageal puncture: voice onset time and vowel duration.

Voice onset time (VOT) and vowel duration characteristics of speakers following the Singer-Blom technique of tracheoesophageal puncture (1980) were compared to those of traditional esophageal and laryngeal speakers. Fifteen subjects in each of the three speaker groups produced the words /pik/, /kap/, /kup/ in a carrier phrase while audio recordings were obtained. Broadband spectrograms were made of the consonant-vowel-consonant (CVC) utterances and vowel duration and VOT were measured. Analysis of variance (ANOVA) procedures revealed that the tracheoesophageal speakers produced significantly shorter VOTs and longer vowel durations than the laryngeal speakers. However, the longer vowel durations for the tracheoesophageal speakers were not completely accounted for by the shorter VOTs found for that group. Spectrographic examination suggests that delayed voice offset time for the tracheoesophageal speakers also contributes to their longer vowel durations. Overall findings indicate that the physical characteristics and motor control properties of the neoglottis, even when driven by pulmonary air as in tracheoesophageal speakers, exert a major influence on alaryngeal voice production.