Using visible speech to train perception and production of speech for individuals with hearing loss

The main goal of this study was to implement a computer-animated talking head, Baldi, as a language tutor for speech perception and production for individuals with hearing loss. Baldi can speak slowly; illustrate articulation by making the skin transparent to reveal the tongue, teeth, and palate; and show supplementary articulatory features, such as vibration of the neck to show voicing and turbulent airflow to show frication. Seven students with hearing loss between the ages of 8 and 13 were trained for 6 hours across 21 weeks on 8 categories of segments (4 voiced vs. voiceless distinctions, 3 consonant cluster distinctions, and 1 fricative vs. affricate distinction). Training included practice at the segment and the word level. Perception and production improved for each of the 7 children. Speech production also generalized to new words not included in the training lessons. Finally, speech production deteriorated somewhat after 6 weeks without training, indicating that the training method rather than some other experience was responsible for the improvement that was found.