Campus News

Published by Communications and Public Affairs (519) 824-4120, Ext. 56982 or 53338

News Release

December 02, 1999

U of G grad student helping design new digital hearing aid

A University of Guelph graduate student is helping develop a new digital hearing aid that can screen out distorting background noise, the No. 1 problem with hearing aid users.

Ed Chau, a master's student in the School of Engineering, is among the millions of people who could benefit from more powerful hearing aids. "I'm not happy with what I have," he said, referring to the devices he has worn for the past seven years to compensate for hereditary hearing loss.

Engineering Prof. Bob Dony added that his new graduate student has excellent qualifications to handle the technical side of this research. "The fact that he wears hearing aids is an interesting addition to his complement of interests."

Newly arrived at Guelph this fall, Chau has a $13,800 a year, post-graduate industrial scholarship jointly funded by the Natural Sciences and Engineering Research Council, U of G and a Waterloo-based company called dspfactory Ltd., a recent spin-off of hearing aid manufacturer Unitron in Kitchener. Established about 18 months ago, the company makes integrated circuits that perform extremely low-powered digital signal processing for potential use in a range of applications. About 5 million hearing aids are fitted every year worldwide, says dspfactory president Dan Murray.

Digital processing power is the key to solving the biggest affliction for users of hearing aids: filtering out background noise. "A lot of the problem that people such as myself have with hearing aids is that speech perception or speech intelligibility decreases dramatically from a quiet to a noisy environment," Chau said.

Processing audio signals properly requires millions of mathematical calculations, a formidable challenge for a miniature chip nestled inside a hearing aid or a cell phone. "There's so much computational power in such a small package. To get it so tiny, you're really pushing the limits of integrated circuit technology," Dony added.

Hearing aids of the future are expected to be equipped with detectors capable of directional processing, permitting the user to focus on a conversation even in the middle of cocktail party rhubarb. "If others around you are not talking to you, you will have less trouble because the hearing aid will help focus on sound coming from in front," explained Chau. His hearing loss is moderately severe, making him unable to pick up high frequencies in particular. "If the phone rings, I won't hear it," he said. "The lower frequencies are mostly okay but I have some loss."

Contact: Prof. Bob Dony, School of Engineering (519) 824-4120, Ext. 3458

Ed Chau, email:

For media questions, contact Communications and Public Affairs, (519) 824-4120, Ext. 3338.

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