Consistency of sentence intelligibility across difficult listening situations.

PURPOSE The extent to which a sentence retains its level of spoken intelligibility relative to other sentences in a list under a variety of difficult listening situations was examined. METHOD The strength of this sentence effect was studied using the Central Institute for the Deaf Everyday Speech sentences and both generalizability analysis (Experiments 1 and 2) and correlation (Analyses 1 and 2). RESULTS Experiments 1 and 2 indicated the presence of a prominent sentence effect (substantial variance accounted for) across a large range of group mean intelligibilities (Experiment 1) and different spectral contents (Experiment 2). In Correlation Analysis 1, individual sentence scores were found to be correlated across listeners in each group producing widely ranging levels of performance. The sentence effect accounted for over half of the variance between listener-ability groups. In Correlation Analysis 2, correlations accounted for an average of 42% of the variance across a variety of listening conditions. However, when the auditory data were compared to speech-reading data, the cross-modal correlations were quite low. CONCLUSIONS The stability of relative sentence intelligibility (the sentence effect) appears across a wide range of mean intelligibilities, across different spectral compositions, and across different listener performance levels, but not across sensory modalities.