MANY hearing aids end up gathering dust because users get fed up with the way they over-amplify traffic noise, muffle conversation, or turn the chink of dinner plates into resounding crashes. Now a new device that automatically adjusts to different environments according to the user鈥檚 preferences could make hearing less of a strain.
Audiologists usually set hearing aids to amplify sounds of different frequencies to different degrees, to help people hear as wide a range of sounds as possible. But one of the big problems is that this adjustment is usually done in quiet clinics, away from the background noises people have to contend with from day to day.
Now a team at Australia鈥檚 Cooperative Research Centre for Cochlear Implant and Hearing Aid Innovation is following a different approach. After the CRC鈥檚 hearing aid has been fitted, the wearer takes over and starts to program it to work in a variety of environments, ranging from clubs, bars and busy streets to quieter surroundings such as libraries.
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In each environment, the user adjusts the volume, and the treble and the bass tone to produce the best sound. A press of a button then stores these settings in memory chips in the hearing aid, along with a sound profile for that environment. The prototype has a sound-processing and remote-control unit mounted on the user鈥檚 belt, though in the finished product the sound processor will be built into the aid itself.
The user 鈥渢rains鈥� the hearing aid for up to 15 different environments. After that, in any new environment, it monitors the ambient sound and uses it in combination with the accumulated data to calculate the best settings for volume and tone. 鈥淚t predicts what settings you鈥檇 like in any environment,鈥� says Justin Zakis, a member of the CRC team. 鈥淎nd the more information the user puts in, the better it operates.鈥�
The team hopes its device, which has been tested on 10 patients so far, will be for sale within two years. It will join a clutch of recent innovations in digital hearing aids that are designed to overcome the problems of background noise, says Jonathan Galt, director of audiology at the National Hearing Centres in Melbourne.
These include microphones that automatically change the direction from which they detect sound to help people who struggle to follow a conversation at a noisy party for example, when sound from all directions is sensed equally, confusing hearing.
The CRC hearing aid will be the first device of its kind that can be customised by the wearer to suit their needs in different sound environments. Zakis says this will give it a big advantage.
Nobody knows exactly how many people suffer deafness severe enough to interfere with conversation, but about 6 million hearing aids are sold worldwide each year. Even people with moderate hearing loss can become depressed and isolated, and their families can be affected as well.
鈥淭he deaf person sits by the television with it blasting away and everybody else avoids them,鈥� says Robert Cowan, director of the CRC. 鈥淎 hearing aid that actually works can reduce stress levels in the family no end.鈥�