Perceptual evaluation and acoustical analyses of 6 kinds of electrolarynges

Abstract

Six different kinds of electrolarynges, which were commercially available in Japan, were compared with regard to the listeners preference and the acoustical characteristics. Listeners were 4 speech therapists who were familiar with electrolarynx speech and 15 university students who had little experience with the device. Sound samples were obtained for each E1 under two conditions: the original sound and the sustained vowels produced by two skilled E1 users with larynges. Perceptual evaluations were performed using Visual Analogue Scale (VAS) on intelligibility, acceptability, noisiness, and naturalness. Speech therapists perceived unnaturalness for an E1 with peculiar F0 declination while naive listeners did not. The lower the perceptual evaluations, the higher the mechanical noise level was found by acoustical analyses. High levels of higher harmonic components were found for the E1’s which had lower perceptual evaluation due to the noise disturbance. Although naive listeners tended to despise E1s with rich higher harmonic components in general, speech therapists did not perceive this as noisiness. Various factors seemed to exist for the listeners preference of E1s. [Work supported by Grant-in-Aid for Scientific Research on Priority Areas (B) Prosody and Speech Processing, Ministry of Education and Sciences.]