An audiovisual test of hearing disability using free-field sentences in noise

Audiovisual speech reception in noise and self-perceived hearing disability in sensorineural hearing loss

Multiple regression analyses were performed on a corpus of data from 56 sensorineurally hearing-impaired subjects. In addition to tonal thresholds, the corpus included simple, quantitative self-ratings for disability and results from speech reception tasks in auditory-only, audiovisual, quiet and noisy conditions. The aim was to evaluate to what extent the predictive power of disability formulas based on the audiogram can be enhanced, when measures derived from speech reception tasks are added to tonal thresholds as supplementary predictors. The better-ear speech reception threshold proved to be a strong exclusive predictor: if speech reception thresholds were introduced into the prediction, the contribution of better-ear pure-tone averages became redundant. Speechreading ability always significantly enhanced the prediction's accuracy. Tonal thresholds or speech reception data combined with lipreading ability scores can explain considerable amounts (42 per cent and 54 per cent, respectively) of the variance in disability ratings. The conclusion is that auditory-only, audiogram-based prediction schemes must not be abandoned, but can be tailored to individuals on the basis of realistic audiovisual speech reception performance.

Lip-reading the BKB sentence lists: corrections for list and practice effects

Two groups of 21 adult subjects with normal hearing viewed the video recordings of the Bamford-Kowal-Bench standard sentence lists issued by the EPI Group in 1986. Each subject viewed all of the 21 lists and attempted to write down the words contained in each sentence. One group lip-read the lists with no sound (the LR:alone condition). The other group also heard a sequence of acoustic pulses which were synchronized to the moments when the talker's vocal folds closed (the LR&Lx condition). Performance was assessed both by loose (KW(L)) and by tight (KW(T)) keyword scoring methods. Both scoring methods produced the same pattern of results: performance was better in the LR&Lx condition; performance in both conditions improved linearly with the logarithm of the list presentation order number; subjects who produced higher overall scores also improved more with experience of the lists. The data were described well by a logistic regression model which provided a formula which can be used to compensate for practice effects and for differences in difficulty between lists. Two simpler, but less accurate, methods for compensating for variation in inter-list difficulty are also described. A figure is provided which can be used to assess the significance of the difference between a pair of scores obtained from a single subject in any pair of presentation conditions.