Aoustical and perceptual characteristics of mandarin consonants produced with an electrolarynx

The electrolarynx (EL) is an electromechanical device that enables patients to produce voice following the surgical removal of their larynx. The purpose of this study is to understand the acoustic and perceptual characteristics of Mandarin consonants produced by EL speakers. First, the acoustic characteristics (including speech intensity, consonant duration, spectral peak, and F2 onset) of Mandarin EL consonants are investigated by comparing the EL and normal consonants. Then, a perceptual evaluation of EL consonants is conducted to identify the relationship between acoustical characteristics and perceptual intelligibility. The results suggest three consonant confusion types are mainly responsible for the poor intelligibility of Mandarin EL consonants: (1) the “unaspirated-for-aspirated” confusion caused by the significantly shortened voice onset time of aspirated consonants; (2) the “voiced-for-voiceless” confusion caused by the continuous pulsing of the EL device and low consonant intensity; and (3) the “perceptual omission” caused by low intensity of consonants and / or consonant omission. The results obtained are promising and potential for further improvements in Mandarin EL speech intelligibility.