The most common causes of hearing loss — age and excessive noise — have different effects on sound processing in the brain, reports a new study in JNeurosci. This finding suggests each type of hearing loss should have its own unique treatment.
Michael Heinz, Kenneth Henry, and colleagues used a chinchilla model of age-related hearing loss to observe how the auditory nerve encodes sounds. Comparing their results to data from a noise-induced hearing loss chinchilla model, the researchers found that the same level of sound sensitivity loss caused more severe processing changes in the auditory nerve of chinchillas with noise-induced hearing loss. Additionally, mild noise-induced hearing loss caused the same amount of processing impairment as moderate to severe age-related hearing loss. These findings indicate a need for hearing-safety awareness, as well as more refined treatments for each type of hearing loss.
Henry, K.S. et al. (2019) Divergent auditory-nerve encoding deficits between two common etiologies of sensorineural hearing loss. Journal of Neuroscience. doi.org/10.1523/JNEUROSCI.0038-19.2019.