Scientists at John Hopkins Medicine have identified a pair of proteins that may help restoring the damaged sound-detecting cells, called hair cells, in humans which can reverse an irreversible hearing loss.

This study is done using genetic tools on mice, explores the process of formation of hair cells on the cochlea, a hollow structure where sound travels in mammals for them to hear. An estimated 90% of genetic hearing loss is caused by problems with hair cells or damage to the auditory nerves that connect the hair cells to the brain. This is because contrary to other mammals, hair cells in humans cannot regenerate, leaving a person with a permanent hearing loss. 

The two proteins that were key to the growth of hair cells in the cochlea have been identified as Activin A and follistatin. These two proteins work in opposite ways, balancing each other, and thereby leading to the timely and organized production of hair cells. Scientists believe this may have the potential to reverse the irreversible hearing loss amongst those suffering from irreversible deafness.