How the ear senses damage caused by noise

Researchers at University College London (UCL) have discovered a basic mechanism that allows cells in our inner ear to respond to the damage caused by loud environmental sounds.

It has long been known that exposure to very loud noise for prolonged periods is damaging to the inner ear but Dr Jonathan Gale, from the soon to be opened Centre for Auditory Research at UCL, has discovered that the kinds of loud sounds we are subjected to every day on crowded and noisy trains and streets, as well as stimulating our delicate sensory hair cells , can trigger a cascade of signals in other non-sensory cells in the inner ear.

Dr Gale, who worked with colleagues from the Venetian Institute of Molecular Medicine in Padova, found that adenosine triphosphate, otherwise known as ATP, is responsible for activating this cascade of signals in tissues of the inner ear. When deliberately damaged, these sensory receptor cells of the hearing organ, the cochlea, released ATP, which then produced a wave of a critical cellular messenger, calcium ions, that spread from the cells surrounding the damaged cell to other cells in the inner ear. Evidence now suggests that the sensory hair cells, as a result of being damaged by the noise, trigger calcium signals in surrounding cells. The signals may act in a positive way to protect or even repair the ear, ear; however further work is required to fully understand their consequences...

These findings help further our understanding of how the ear reacts to damage, not only by loud, prolonged noise, but also by loud sound for just short periods; exactly the kind of sound we are subjected to every day in noisy streets and trains, in workplaces, and in the use of personal audio players

Dr Gale says: "We are just beginning to understand how cells within the inner ear respond to noise damage. By understanding how they respond we can begin to determine ways to help repair damaged ears. "

Notes for Editors

•  To obtain a copy of the paper or to arrange an interview with Dr Gale, please contact Heidi Foden , UCL Media Relations, 020 7679 7678 or h.foden@ucl.ac.uk

•  The Centre for Auditory Research Centre based at UCL is the largest auditory research centre in the UK and carries out cutting-edge collaborative research into disorders of hearing and balance. It is funded by a £9m Joint Infrastructure Fund (JIF) award from the Wellcome Trust.