Individual speaker influence on relative intelligibility of esophageal speech and artificial larynx speech

Comparisons were made of the relative intelligibility of esophageal and artificial larynx speech. Care was taken to minimize the variable effects of individual speaker characteristics. For example, rather than relying solely on data comparisons between groups of different speakers, contrasts were also made between samples from subjects who could use both means of alaryngeal speech. Fifteen proficient male laryngectomized speakers were selected. Five used only esophageal speech, five used only artificial larynx speech, and five produced both forms of speech. Recordings were made while the subjects read 50 PB (Phonetically Balanced) words embedded in a carrier phrase and were transcribed by 30 naive listeners. Differences in intelligibility between esophageal and artificial larynx speech resulted when data comparisons were based on different speaker groups. However, differences were not evident when data from the same speakers were compared. The results were interpreted to highlight the possible influence of individual speaker characteristics, rather than differences between communication methods.