Hearing quality improved with bionic ear technology

In a breakthrough, scientists have for the first time used electrical pulses delivered from a cochlear implant to deliver gene therapy, thereby successfully regrowing auditory nerves.
The research also heralds a possible new way of treating a range of neurological disorders, including Parkinson's disease, and psychiatric conditions such as depression through this novel way of delivering gene therapy.
"People with cochlear implants do well with understanding speech, but their perception of pitch can be poor, so they often miss out on the joy of music," said The University of New South Wales (UNSW) Professor Gary Housley, who is the senior author of the research paper.

"Ultimately, we hope that after further research, people who depend on cochlear implant devices will be able to enjoy a broader dynamic and tonal range of sound, which is particularly important for our sense of the auditory world around us and for music appreciation," said Housley.
The work centres on regenerating surviving nerves after age-related or environmental hearing loss, using existing cochlear technology.
The cochlear implants are "surprisingly efficient" at localised gene therapy in the animal model, when a few electric pulses are administered during the implant procedure.

"This research breakthrough is important because while we have had very good outcomes with our cochlear implants so far, if we can get the nerves to grow close to the electrodes and improve the connections between them, then we'll be able to have even better outcomes in the future," said Jim Patrick, Chief Scientist and Senior Vice-President, Cochlear Limited.

It has long been established that the auditory nerve endings regenerate if neurotrophins - a naturally occurring family of proteins crucial for the development, function and survival of neurons - are delivered to the auditory portion of the inner ear, the cochlea.
But until now, research has stalled because safe, localised delivery of the neurotrophins can't be achieved using drug delivery, nor by viral-based gene therapy.
Housley and his team developed a way of using electrical pulses delivered from the cochlear implant to deliver the DNA to the cells close to the array of implanted electrodes. These cells then produce neurotrophins.

"No-one had tried to use the cochlear implant itself for gene therapy. With our technique, the cochlear implant can be very effective for this," said Housley.
The research was published in the journal Science Translational Medicine.