Audition, speech and bionic ear design
Audition (hearing) is the primary sense required for speech. It also plays a major role in language. Audition involves the transduction of sound waves from the ear drum in the outer ear to the cochlear in the inner ear. Within the cochlear vibrations associated with the sound waves are transformed into electrical signals which are relayed to the brain via neurons in the auditory nerve. The brain interprets these signals and uses them to perceive sound.
There are two common causes of hearing impairment.
- The first is a reduction in the ability to transduce vibrations from the outer to the inner ear. This requires a hearing aid to increase the amplitude of the sound waves entering the ear in order to compensate for the weak transduction of sound vibrations.
- The second is the inability of the inner ear to stimulate auditory nerve neurons and transmit sound information in the brain. When this is caused by the inability to transform the sound vibrations into electrical signals at the inner ear/auditory nerve interface one solution is the cochlear implant. This is a surgically implanted device that detects sound waves using a microphone, transforms these sound waves into electrical signals, and stimulates the auditory nerve so sound information can be transmitted to the brain.
Research goals
Our research goal is to study, understand and improve technology for the hearing impaired.
Research projects include:
- cochlear implant design
- hearing-aid design
- neural modelling of the auditory system
- sound localisation
- speech processing
- speech recognition.