Effect of subsequent context on the real-time interpretation of ambiguous target words in spectrally degraded speech

Abstract

Subsequent context in a sentence can be used to revise the interpretation of a word that was not clearly heard, a frequent occurrence in degraded speech. One strategy for avoiding the cognitive cost associated with revising an initial interpretation is to delay commitment to an interpretation until the end of the sentence, sometimes called a “wait-and-see” strategy. Listening with a significant hearing loss (i.e., constantly hearing degraded speech), may prompt a listener to use this strategy even in relatively easy listening conditions. This study used an eye-tracker to record gaze patterns during a phoneme classification task of ambiguous target words in two levels of background noise ( + 5 and −5 dB SNR). Participants either used cochlear implants (CIs) or were presented 8-channel noise vocoded speech. The target words were at the beginning of sentences; the subsequent context cued one target word interpretation (based on phoneme classification) or the other. We hypothesized that listeners who use CIs will demonstrate a delaying strategy at both levels of background noise, while listeners who have acoustic hearing will only demonstrate a delaying strategy at the highest level of background noise. These findings have implications for rehabilitative strategies to improve communication outcomes in adults with CIs.