Recent studies are being performed to improve and restore hearing of mice lacking the gene required for hearing.  The experiment utilizes gene therapy to target the inner ear hair cells, which send neural inputs of balance and hearing.  Scientists used a combination of a virus gene-carrier, adeno-associated virus (AAV), and exosomes, a protective cellular “bubble,” as a vehicle for the gene therapy.  This combined method was found to allow the gene to bind to the hair more effectively, compared to using only AAV.  The findings showed that nine of the twelve mice treated with this form of gene-therapy saw improvement in hearing and balance.  While this study is ongoing, it will be years before the experiment is tested on human subjects.