A Voice-Activated Switch for Persons with Motor and Speech Impairments: Isolated-Vowel Spotting Using Neural Networks
|Shanqing Cai (Google, USA), Lisie Lillianfeld (Google, USA), Katie Seaver (Google, USA), Jordan R. Green (Google, USA), Michael P. Brenner (Google, USA), Philip C. Nelson (Google, USA), D. Sculley (Google, USA)|
Severe speech impairments limit the precision and range of producible speech sounds. As a result, generic automatic speech recognition (ASR) and keyword spotting (KWS) systems fail to accurately recognize the utterances produced by individuals with severe speech impairments. This paper describes an approach in a simple speech sound, namely isolated open vowel (/a/), is used in lieu of more motorically-demanding utterances. A neural network (NN) is trained to detect the isolated open vowel uttered by impaired speakers. The NN is trained with a two-phase approach. The pre-training phase uses samples from unimpaired speakers along with samples of background noises and unrelated speech; then the fine-tuning phase uses samples of vowel samples collected from individuals with speech impairments. This model can be built into an experimental mobile app to act as a switch that allows users to activate preconfigured actions such as alerting caregivers. Preliminary user testing indicates the vowel spotter has the potential to be a useful and flexible emergency communication channel for motor- and speech-impaired individuals.