Effect of eye closure on speech recognition in noise: in light and in darkness

This study evaluated whether listening with an eye closure (EC) strategy improves speech recognition in noise (SRN) under different visual conditions. Previous research suggests EC may enhance activation of cortical systems involved in listening and attention. Study hypotheses were that EC listening leads to better SRN than eyes open listening, that listening in darkness leads to better SRN than in light, and EC listening leads to more improved SRN in light compared to darkness.

SRN with the Cantonese Hearing in Noise Test (CHINT) under four conditions was assessed: (1) eyes open with lights on, (2) EC with lights on, (3) eyes open in darkened room, and (4) EC in darkened room. ANOVA determined potential differences among conditions and effect sizes were calculated.

Fifty-six young adults (age range 18-35 years) with bilaterally normal hearing.

Significant effects for EC and presence/absence of an external visual stimulus on SRN were found. Post-hoc analysis found a statistically significant difference between eyes open and closed in light, with a large effect size, indicating EC resulted in the greatest improvement in SRN when in the presence of an external visual stimulus. However, differences compared with known CHINT inter-list variability lacked clinical importance.

EC did significantly improve SRN and is a potential strategy for challenging listening situations when feasible, although no changes are needed for CHINT norms or testing procedures in relation to EC status.