A trial in China involving an adeno-associated virus (AAV) based gene therapy delivering the OTOF gene demonstrated hearing improvements in ten participants aged 1.5 to 23.9 years with autosomal recessive deafness. Using a synthetic AAV vector administered via cochlear membrane injection, patients showed rapid hearing gains within a month and sustained improvements after six months, with an average perceptible sound volume reduction from 106 to 52 decibels. Published in Nature Medicine, the results mark progress in expanding therapeutic options beyond children to adolescent and adult populations.