The effect of semantic predictability on word intelligibility in natural and spectrally degraded sentences

One of the most consistent findings across a wide range of methodologies and stimuli is the positive effect of semantic context and predictability on speech intelligibility. However, there is evidence that this may not be true for a limited range of stimuli. The present study investigated how sentences with spectrally-limited acoustic information constrained the use of semantic predictability in speech perception. This was studied by presenting listeners with spectrally-degraded and natural-speech sentences with high- and low-predictability words. The SPIN sentence lists and the associated multi-talker babble was used (Bilger, 1984). The results demonstrated that listeners benefited from high predictability in both cases but the degree of this effect was not equal. High predictability aided the perception of natural and 8-band speech equally. In contrast high predictability had a significantly smaller effect on speech intelligibility for 4-band speech. These findings are of special interest to investigations of speech perception in individuals with poor frequency representation such as those with cochlear implants.