A speech-controlled environmental control system for people with severe dysarthria.
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.
Hawley
Mark S
MS
Department of Medical Physics and Clinical Engineering, Barnsley Hospital NHS Foundation Trust, UK. mark.hawley@nhs.net
Enderby
Pam
P
Green
Phil
P
Cunningham
Stuart
S
Brownsell
Simon
S
Carmichael
James
J
Parker
Mark
M
Hatzis
Athanassios
A
O'Neill
Peter
P
Palmer
Rebecca
R
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