title: A speech-controlled environmental control system for people with severe dysarthria.
abstract: Automatic speech recognition (ASR) can provide a rapid means of controlling electronic assistive technology. Off-the-shelf ASR systems function poorly for users with severe dysarthria because of the increased variability of their articulations. We have developed a limited vocabulary speaker dependent speech recognition application which has greater tolerance to variability of speech, coupled with a computerised training package which assists dysarthric speakers to improve the consistency of their vocalisations and provides more data for recogniser training. These applications, and their implementation as the interface for a speech-controlled environmental control system (ECS), are described. The results of field trials to evaluate the training program and the speech-controlled ECS are presented. The user-training phase increased the recognition rate from 88.5% to 95.4% (p<0.001). Recognition rates were good for people with even the most severe dysarthria in everyday usage in the home (mean word recognition rate 86.9%). Speech-controlled ECS were less accurate (mean task completion accuracy 78.6% versus 94.8%) but were faster to use than switch-scanning systems, even taking into account the need to repeat unsuccessful operations (mean task completion time 7.7s versus 16.9s, p<0.001). It is concluded that a speech-controlled ECS is a viable alternative to switch-scanning systems for some people with severe dysarthria and would lead, in many cases, to more efficient control of the home.
authors.affiliation: Department of Medical Physics and Clinical Engineering, Barnsley Hospital NHS Foundation Trust, UK. mark.hawley@nhs.net
authors.forename: Mark S
authors.initials: MS
authors.lastname: Hawley
authors.forename: Pam
authors.initials: P
authors.lastname: Enderby
authors.forename: Phil
authors.initials: P
authors.lastname: Green
authors.forename: Stuart
authors.initials: S
authors.lastname: Cunningham
authors.forename: Simon
authors.initials: S
authors.lastname: Brownsell
authors.forename: James
authors.initials: J
authors.lastname: Carmichael
authors.forename: Mark
authors.initials: M
authors.lastname: Parker
authors.forename: Athanassios
authors.initials: A
authors.lastname: Hatzis
authors.forename: Peter
authors.initials: P
authors.lastname: O'Neill
authors.forename: Rebecca
authors.initials: R
authors.lastname: Palmer
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D003143:Communication Devices for People with Disabilities; D004401:Dysarthria / Q000534:rehabilitation*; D004780:Environment, Controlled; D006801:Humans; D010363:Pattern Recognition, Automated / Q000379:methods*; D012985:Software Design; D013018:Sound Spectrography / Q000379:methods*; D049250:Speech Recognition Software; D014584:User-Computer Interface