A study of a human interface device controlled by formant frequencies for the disabled

Abstract

We propose a human interface device using a formant frequency. It does not require complicated signal processing. The formant frequency means vocal tract resonance frequency which characterizes the phonemes. By using a microphone, we think it is possible to estimate the position of tongue and the opening of mouth. We investigated the relationship of formant frequencies and the manner of articulation. At first, we clarified the range of the formant frequencies by moving the mouth and the tongue freely. Next, we set the horizontal and vertical axes which correspond to the second- and first-formant frequencies respectively on a computer display screen. Subjects were asked to fit a mouse pointer controlled by their formant frequencies to a target appeared on a display. It is concluded that subject can be relatively easy to control the pointer within the range enclosed by five Japanese vowels formant points. © 2013 Springer-Verlag Berlin Heidelberg.