Pseudo-Pitch and Distorted Words: An Interface Modality for Dysarthric UsersBy Fimbel, Eric J.; Lemieux, Michael; Challenges for Assistive Technology: AAATE 2007 Conference Proceedings, pp. 357-362
Publication Date: 2007
Presentation of a sound-based alternative and augmentative communication (AAC) interface for dysarthric speakers. Dysarthria, or impaired speech articulation, co-occurs with disorders such as cerebral palsy, lateral amyotropic sclerosis (ALS), Parkinson’s disease, and stroke. The system presented consists of a head-mounted microphone connected to a personal computer. The user enters either discrete or analog commands via the microphone. Discrete commands are user-dependent and correspond to a predetermined set of words such as “enter,” “erase,” or “help,” whereas analog commands are unvoiced sounds such as inhaling or exhaling. An audio card digitizes the signal, and a computer program processes the signal and produces commands. The system provides visual feedback in the form of bars of variable length scrolling on the computer screen. The system discriminates between discrete and analog commands by means of the variance in pitch, as voiced sounds are significantly lower in pitch than unvoiced sounds. The analog commands produced can be used, for example, for computer-screen cursor control. An off-line version of the system using commands from the Whitaker database of dysarthric speech was tested with 7 speakers, of whom 6 were dysarthric. Performance, which depended markedly on the severity of the disability, showed a rate of success varying from 48 to 96 percent among dysarthric participants. Implications for further research to improve the interface are discussed.
Published by: IOS Press (Website:http://www.iospress.nl)
Association for the Advancement of Assistive Technology in Europe (AAATE) (Web Site: http://www.aaate.net )
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