Evaluation of electrolarynx controlled by real-time statistical F0 prediction

Abstract

One of the major speaking methods for laryngectomees is a speaking method using an electrolarynx to generate artificial excitation sounds, instead of vocal fold vibration. Although electrolaryngeal (EL) speech is relatively intelligible, its naturalness is quite low owing to the artificial excitation sounds. To make it possible to produce more naturally sounding EL speech, we have proposed an automatic control method of the fundamental frequency (F0) patterns of the excitation sounds generated from the electrolarynx based on real-time statistical F0 prediction. In this method, a vibration of the electrolarynx to generate the excitation sounds is controlled not according to additional signals consciously provided by the laryngectomees but using only their produced EL speech signals. In the previous report, we have developed a prototype system by implementing our proposed method to the electrolarynx and have evaluated its performance objectively through a simulation. In this paper, we evaluate its performance subjectively in terms of naturalness and intelligibility. The experimental results demonstrate that the prototype system can produce more natural EL speech while maintaining its high intelligibility compared to the conventional electrolarynx. [This research was supported in part by JSPS KAKENHI Grant Nos. 15J10727 and 26280060.]