The interactions of amplitude and phonetic quality in esophageal speech.

Levels of isolated vowels and the influence of consonant environment on vowel level were determined for three esophageal speakers and three normal speakers. Twenty lists of isolated vowels and diphthongs and 576 monosyllabic words were used as the stimuli. The results revealed that esophageal speakers had an 11-dB reduction in SPL compared to normal speakers. The greatest level was observed on the vowels /i/ and /u/. Differences between normal and esophageal speakers are discussed in terms of absolute level and phonetic environment.