Cochlea model reveals inner workings of the ear

A model developed at Victoria University of Wellington has helped researchers conduct intricate experiments into the cochlea, which may lead to improved methods of treatment for hearing impairments.

PhD student Mohammad Ayat’s research involved developing a model of the cochlea, a snail-shaped chamber in the human ear, focused on the cochlear microphonic (CM)—an electrical signal generated inside the cochlea in response to sound.

The model—which includes electrical coupling of the cochlea—is the most detailed one-dimensional model developed to date, and allowed Mohammad to predict some characteristics of the cochlear microphonic.

“Some of these characteristics are different from what many researchers thought in the past, and may have clinical significance once further research is done,” says Mohammad.

Mohammad says the cochlear microphonic signal is a potential tool for diagnosing hearing impairments and investigating cochlear function.

“The CM can provide information about the health of particular sections of the cochlea, which may lead to faster and more accurate methods of adjusting the many settings of modern hearing aids to compensate for areas of weakness.

“The cochlea is hard to study because of where it is in the body and the complex processes at work. Modelling allowed us to bridge these gaps and gain useful information.”

Mohammad, who had no previous experience researching the cochlea, says it took him around eight months to learn its functionality.

“It’s a fascinatingly complex organ and there’s still mystery around how it works. Further modelling and signal processing experiments will lead to better methods of diagnosis, and improved methods of treatment for hearing impairments. It may also lead to the development of bionics-inspired speech recognition systems similar to the human cochlea.”

This study was conducted at Victoria University of Wellington, under the supervision of Dr Paul Teal from the School of Engineering and Computer Science and Professor Mark McGuinness from the School of Mathematics, Statistics and Operations Research.

Mohammad will graduate with a PhD in Electronic and Computer Systems Engineering on Wednesday 13 May 2015.