Decades of research on noise-induced hearing loss has shown that acoustic overexposure leads to hair cell damage which can cause elevation in hearing thresholds. Recent research suggests that noise exposure can lead to loss of spiral ganglion cells, even when hair cell recovers and hearing thresholds returns to normal. This cochlear synaptopathy is referred as “hidden hearing loss” because the neural degeneration does not elevate behavioral hearing thresholds but it can significantly impaired supra-threshold listening skills. Our research demonstrated that the medial olivocochlear (MOC) system which is one of two efferent systems that influence cochlear functioning, becomes hyperactive in response to intense noise exposure. The hyperactive MOC system is hypothesized to be associated with tinnitus and hyperacusis. This hypothesis is under investigation.
Bhatt, I. (2017). Increased medial olivocochlear reflex strength in normal-hearing, noise-exposed humans. PloS ONE, 12(9):e0184036. PubMed [journal] PMID: 28886123, PMCID: PMC5590870 [PDF]
Bhatt, I. (2017). Extended high-frequency audiometry and DPOAEs in “normal” hearing noise-exposed young adults. Research Poster Presentation at American Speech and Hearing Association Conference 2017. Los Angeles, CA. [Poster]
Mbuoben, T., Tubbs, H., Randall, A., White, N, Hiebert, C., Bhatt, I. (2016). Transient-Evoked Otoacoustic Emissions in Normal-Hearing Noise-Exposed Human Ears. Research Poster Presentation at American Speech Language and Hearing Association 2016. Philadelphia, PA. [Poster]