Hearing thresholds correlate more strongly with speech intelligibility at low signal-to-noise ratios.

Evidence

The main effect of PTA reflected the fact that average audiometric threshold was negatively correlated with intelligibility in all listening situations. The interaction with SNR occurred because the correlations tended to be greater for low SNRs than high SNRs. This was particularly true for the sentence stimuli leading to the three-way interaction (Type * SNR * PTA). — Dijk, Pim van, Physiology, Psychoacoustics and…, 1229