Selected acoustic characteristics of emerging esophageal speech: Case study

Abstract

The development of esophageal speech was examined in a laryngectomee subject to observe the emergence of selected acoustic characteristics, and their relation to listener intelligibility ratings. Over a two-and-a-half  month period, the data from  five recording sessions was used for spectrographic and perceptual (listener) analysis. There was evidence to suggest a fairly reliable correlation between emerging acoustic characteristics and increasing perceptual ratings. Acoustic factors coincident with increased intelligibility ratings appeared related to two dimensions: firstly, the increasing pseudoglottic control over esophageal air release; secondly the presence of  a mechanism of  pharyngeal compression. Increased pseudoglottic control manifested  in a reduction of  tracheo-esophageal turbulence, and a more efficient  burping mode of  vibration with clearer formant structure. Spectrographic evidence of  a fundamental  frequency  did not emerge. These dimensions appeared to have potential diagnostic and therapeutic value, rendering an analysis of  the patient's developing vocal performance  more explicit for  both clinician and patient.