YOUNG INVENTORS AWARDS: WINNERS: SILVER AWARD

Music to My Ears

An Australian inventor and wannabe rock star has developed a piece of software that could strike a chord with deaf people

By Michelle Innis/SYDNEY

Issue cover-dated November 28, 2002

ROBERT FEARN'S neighbours in Wagga Wagga, rural New South Wales, may have wished the eight-year-old trumpeter was less passionate about music.

Fearn, now 31, says constant lessons and an early love of melodies inspired his work in recapturing music for adults with hearing loss. Fearn has developed a piece of software that improves pitch perception in the cochlear implants that help deaf people hear speech. His "Multi-rate cochlear stimulation: a bionic ear with pitch" was granted the Silver Award in the REVIEW'S Young Inventors Awards this year. Fearn hopes it will allow profoundly deaf children to hear music.

"I've always been interested in music and I've always wanted to help people in a very direct way," says Fearn, now based in Cambridge, Britain, and working on mobile-telephone positioning systems.

Fearn's doctoral-degree research, which was completed at the University of New South Wales in Sydney in 2001, improves the sound quality in existing cochlear implants, so that wearers can better hear pitch.

"Music and speech carry information in different ways," explains Joe Wolfe, a professor at University of NSW School of Physics and one of Fearn's degree supervisors. "In music, you must know the pitch of a note accurately and there may be several notes heard simultaneously. The information in speech is carried in broad bands of high frequencies."

Western languages, for example, use a limited range of tones and the tone, or pitch, carries very little of the meaning of what is being said.

Acoustics expert Neville Fletcher, a professor at the Australian National University's Research School of Physical Sciences and Engineering says: "The implant as it stands captures speech and with Robert's work it will capture music. People can hear everything in-between, including tonal languages."

A cochlear implant involves several components: First, an electrode array with 22 electrodes along it is implanted into the cochlea, or inner ear.

In deaf people, the hair cells that trigger the inner-ear nerves don't work. Normally, they would detect sound signals and send them to the brain. The electrodes attempt to replicate this by stimulating the nerves directly with electronic pulses.

A small electronic device, implanted into the skull, drives the electrodes. This device receives signals from a processor carried on a belt or in a pocket. The processor includes a microphone that picks up noise and translates it into electrical signals, which are then transformed into a digital format. The digital signals are sent to the electrodes along the array. The brain decodes the digital messages that are heard as some form of noise, though pitch is not distinguished.

Fearn says people with cochlear implants could hear speech well but music was harsh. Rhythm could be detected but harmony and melodies were lost because the translation of sound into pulses was not optimized for music.

"A volunteer said listening to music while wearing a cochlear implant was like the sound of cellophane being screwed up," says Wolfe. Wearers also found it difficult to hear speech if music was playing. And a meal at a restaurant could be a nightmare: The racket of competing speech and music would drive the wearer home.

"Once people can hear speech they say 'this is a good part of life'," Fearn says. "The next biggest request is 'I want to hear music.' This is especially true of young people who are afraid to go out to meet friends because background music is played everywhere and it obscures speech."

Fearn's software, still in the trial phase but already patented, decodes music and sends digital signals to the 22 electrodes along the array inside the cochlea.

It's still early days. "Power consumption and memory are issues," Wolfe says. "But we have a strategy that has been patented and it gets good feedback." Sydney's Cochlear Implants holds the patent after splitting the cost of funding Fearn's doctoral work with the government.

And Fearn's musical ambitions? He gave up the trumpet at 14 and took up the guitar. "When the teenage years set in you realize not too many rock stars play trumpet."

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