Artificial speech production device for laryngectomees controlled by jaw and tongue movements

Abstract

The purpose of this study is to develop an artificial speech production device for laryngectomees. The device is composed of three parts, a measurement part for jaw and tongue movements, an estimation part for the formant frequencies, and a voice synthesizer. This paper argues that the formant frequencies of vowels can be estimated from tongue and jaw movements of the subject, and that based on this information, continuous vowels can be produced using a voice synthesizer. Curvature of midsagittal tongue surface is measured with piezoelectric film. The degree of the jaw opening is estimated by the electrical impedence between right and left buccalis. Experimental results suggest that the formant frequencies can be determined from the curvature of the tongue surface and the jaw opening. Therefore, a mapping function is introduced to obtain the formant frequencies for the synthetic speech. The amplitude and pitch of the voice are controlled manually by the person who wears the device. The articulation score of the voice produced by the device was 95% for isolated vowels and 90% for connected vowels. Results showed the usefulness of the proposed device.