Making Dysarthric Speech Intelligible

Oregon Health & Science University, Portland OR

Investigators

Abstract

Making Dysarthric Speech Intelligible This is the first year funding of a three year continuing award. Of the 2.5 million or more adult Americans with significant disability due to chronic neurologic impairment, a large percentage present with dysarthria, or speech impairment, as one of their disabling conditions, and there are no known cures. Dysarthric individuals report loss of employment, educational opportunities, social integration, and quality of life. Despite some strategies for compensating, the isolation caused by communication impairment is pervasive. In this project, the PI will develop new algorithms that, when implemented in wearable devices, will enable dysarthric individuals to be more easily understood. Currently available devices are essentially (digital or analog) spectral filters and amplifiers that enhance certain parts of the spectrum. While these can help certain types of dysarthria, many dysarthric persons suffer from speech problems that require forms of speech modification that are much more profound and complex such as: irregular sub-glottal pressure, resulting in loudness bursts that can be difficult to adjust to; absence, or poor control, of voicing; systematic mispronunciation of certain phoneme groups, resulting in certain sounds becoming indistinguishable or unrecognizable; variable mispronunciation; and poor prosody (pitch control, timing, and loudness). For these difficult problems, new approaches are needed that do not merely filter the speech signal but analyze it at acoustic, articulatory, phonetic, and linguistic levels. These approaches can be combined to generate an output speech signal that, while preserving certain features of the input speech, modifies the input speech along as many dimensions as is needed to achieve intelligibility. The past decade has seen a revolution in speech technology that can be applied to these problems; while little of the currently developed technologies are in their present form applicable to dysarthria, the underlying algorithms can form a basis for the creation of innovative techniques that are specifically targeted to address these more difficult speech problems. The PI will create these technologies in a diagnostic framework, so that the appropriate technology is used for a given type of dysarthria. The results will be of great value for dysarthric individuals; the scientific challenges are formidable, and meeting them will produce insights that will be broadly useful for other speech technologies as well.