Washington, Jan 14: “What is music to your ears might be noise to others,” this phrase seems quite true as a new study has revealed that if you could hear the world through someone else's ears it would sound very different to what you are used to.

The study by scientists funded by the Biotechnology and Biological Sciences Research Council (BBSRC) was on the co-operation of brain and ears to understand the acoustic environment. It was found that the part of the brain dealing with sound, the auditory cortex, is adapted in each individual and tuned to the world around us.

The study at the University of Oxford, led by Dr Jan Schnupp, a research leader at the University of Oxford Auditory Neuroscience Group, suggests that we learn to localise and identify different sounds, all through our lives. This phenomenon of picking up subtle clues about the identity and source of a particular sound could help to develop more sophisticated hearing aids and more effective speech recognition systems.

For the study, the scientists studied the auditory cortex of the brain and found that not only acoustical properties, like frequency and pitch, but also statistical properties of the sound-scape, determine its responses.

There is a constant change in loudness and pitch around us. Subtle and gradual changes in the soundscape are statistically more regular than large and sudden changes. It was found that our brains are adapted to the former. The neurons in the auditory cortex appear to anticipate and respond best to gradual changes in the soundscape.

"Our research to model speech sounds in the lab has shown that auditory neurons in the brain are adaptable and we learn how to locate and identify sounds. Each person's auditory cortex in their brain is adapted to way their ears deliver sound to them and their experience of the world. If you could borrow someone else's ears you would have real difficulty in locating the source of sounds, at least until your brain had relearned how to do it,” said Dr. Schnupp.

Dr Schnupp has also found that the auditory cortex does not have neurons sensitive to different aspects of sound. When the researchers look at how the auditory cortex responds to changes in pitch, timbre and frequency they saw that most neurons reacted to each change.

He explained: "In the closely related visual cortex there are different neurons for processing colour, form and motion. In the auditory cortex the neurons seem to overwhelmingly react to several of the different properties of sound. We are now investigating how they distinguish between pitch, spatial location and timbre.

"If we can understand how the auditory cortex has evolved to do this we may be able to apply the knowledge to develop hearing aids that can blot out background noise and speech recognition systems that can handle different accents,” he added.

“This research is revealing how our senses work and how the brain interprets information from the ears. These BBSRC-funded studies of a fundamental biological process may bring exciting developments in helping people with hearing and other disabilities,” said Professor Nigel Brown, BBSRC Director of Science and Technology.

The study is featured in the current issue of BBSRC Business. (ANI)