Scientists use gene therapy to make deaf mice hear again:

• Scientists restored hearing ability of deaf mice by using a engineered virus to replace the defective genes in the mouse. 
• The process of using a virus to transfer a gene into an organism is called Transduction.
• Scientists are still figuring out to use gene therapy effectively in humans to cure genetic disorders, just like in mice.

Source: "Gene therapy restores auditory and vestibular function in a mouse model of Usher syndrome type 1c"