Sydney scientist develops new hearing software

A University of Sydney scientist has developed a software algorithm which improves the ability of the hearing-impaired to hear in noisy environments.

Craig Jin, from the School of Electrical and Information Engineering at the University of Sydney, is a finalist in the 2005 Fresh Innovators program in recognition of his leading role in the development of the software.

According to Jin, 22 per cent of Australia's population, or 3.25 million people, are hearing impaired. By the age of 70 years, three in four people need hearing aids - this age-related hearing loss usually occurs initially in the high frequency sounds, the frequency that speech falls into. However, only one in five people seek help for this, and of these, 12 per cent return their hearing aids, presumably because they are not happy with them.

The Spatial Hearing Aid technology that Jin has come up with increases the ability of hearing aids to work in noisy environments, for example where there are multiple people talking. It does this by enhancing the ability of the hearing aid to detect the spatial environment. Rather than focusing on getting more speech signals to a hearing aid, Jin's approach focuses on providing the brain with extra information associated with the shape of the outer ear.

"It is a new approach," said Jin. "There is only so much you can do with signal processing and the speech signals that hearing aids can now obtain are good quality. With our approach we are trying to provide the brain with more sound information."

The algorithm works by taking high frequency information associated with the outer ear -- such as direction the speech is coming from -- and moves the speech signals down to a lower frequency that a hearing impaired person can hear. This enables the person to segregate who is speaking and thus increases intelligibility of speech when there is more than one person talking.

"The wearer would need to adapt and relearn to hear speech at this lower frequency," said Jin. "We believe the brain can adapt to this, the outer ear keeps changing as we get older and we adapt to this. We have just started clinical trials with the National Acoustic Laboratories to assess primarily this, which will probably take several months."

The spin off company VAST Audio has been established to commercialise the software and focus on contacting hearing aid manufacturers. The Spatial Hearing Aid technology can be integrated with already existing hearing aids, and Jin said their initial target would be the high-end hearing aids that sit in the ear canal. This would require a three year roll-out period since these hearing aids are made with a hard wired chip and integration of the technology would need to occur at the manufacturing stage.