Unilateral Hearing Loss and Brain Changes
Liu et al (2015) report that sensorineural hearing loss (SNHL) may be due to multiple etiologies, such as noise exposure, aging, infections, ototoxic chemicals, vascular compromise, disruption of cochlear membranes, inner ear abnormalities, immunologic disorders, and more. However, they report that it is rare to have a single specific etiology attributed to an individual. Regardless of the specific etiology, “the relationship between the auditory cortex and SNHL is not fully clarified.” The authors report that auditory deprivation (secondary to hearing loss) does lead to changes in functional auditory cortex activity.
Functional MRI data was gathered on 19 people (2012-2013) with longstanding (greater than one year) SNHL in their left ears and normal hearing in their right ears. All left ears had pure-tone averages (PTAs) greater than 70 dB HL and all right ears had PTAs better than 25 dBHL. The control group included 35 people with normal hearing in both ears.
Liu et al report that “abnormal functional connectivity in the auditory system occurs following unilateral auditory deprivation…” and these results “indicate that an adaptive reorganization occurred….”
For More Information, References, and Recommendations
Liu B, Feng Y, Yang M, Chen J, Li J, Huang Z, Zhang L. (2015) Functional Connectivity in Patients with Sensorineural Hearing Loss Using Resting State MRI. American Journal of Audiology 24:145-152.