The effect of medial olivocochlear reflex enhancement associated with temporal expectation on listening performance in noise

Abstract

The medial olivocochlear reflex (MOCR) is efferent feedback activated by acoustic stimulation and plays a role to improve signal detection in noise. We have reported that the MOCR and phase locking value (PLV) of delta oscillations showed a similar decreasing tendency with increasing jitter added to the preceding sound sequence. This suggests that the processing at the cortical regions is involved in the regularity -based enhancement of MOCR. Further, the dependency disappeared as the load of the interfered task increased, suggesting that the cortical predictive control of MOCR requires top-down attention to sounds. Considering the anti-masking effect of MOCR, MOCR enhancement with anticipation may improve listening performance in noise. We extended our previous experiments by measuring listening performance in noise and compared its dependence on the jitter size with MOCR strength and PLV of delta oscillation. In the low load condition, the three indices increased with decreasing the jitter. In the high load condition, by contrast, the dependency on the jitter size disappeared. The similarities of the indices in the dependency on jitter size and attention implicate that the cortical predictive control can facilitate the antimasking of MOCR, therefore improving the listening performance in noise.