Brain to blame for lame hearing at cocktail parties?
Hidden secrets of the brain revealed for Brain Awareness Week 2010 (15-21 March)
Do you struggle to hear properly at parties and at other group gatherings? If so, you are not alone and your brain- rather than your ear – could be to blame for this inability to zoom in on the person you want to hear. New research undertaken by Deafness Research UK scientists at the UCL (University College London) Ear Institute is leading to a greater understanding of the role of the brain in auditory processing. The brain appears to play a greater role than was previously understood and unravelling its secrets offers new hope for the deaf and hard of hearing, and in particular, the cocktail party problem.
Current research centres on how we as humans manage to hear speech in noisy backgrounds. The so-called cocktail party problem is nothing to do with drinks, but is rather the term coined to describe the brains ability to focus our listening attention on a single speaker amid a mixture of conversations, background noises and other distractions. Little is known about the cocktail party problem, and further research will benefit deaf and hard of hearing people; particularly those with cochlear implants or bionic ears and hearing aids, as these devices struggle in noisy environments.
The UCL Ear Institute laboratory is one of the leading international research groups investigating binaural hearing the ability to process sounds using both ears.
This ability enables most of us to talk in a noisy place, blocking out other sounds to hear our friend/s, but, at the same time, to respond immediately if someone calls our name. The ability can be critical and early research in the 1950s focused on the problems faced by air traffic controllers, when multiple messages were received from pilots over a single loudspeaker. If you consider todays busy hospital emergency room, with several people shouting vital instructions at once, you can appreciate the significance of the cocktail party effect.
Vivienne Michael, Chief Executive of Deafness Research UK, said: Scientists are particularly interested in how the central auditory system is able to cope with noisy environments; a major challenge for hearing research over the next decade will be to improve the performance of cochlear implant devices. Bionic hearing provides a remarkable chance for the deaf to hear, sometimes for the very first time.
The work of the Ear Institute is essential for those with hearing problems and we continue to fund some of its most vital and groundbreaking research. We are only just beginning to appreciate the role the brain and this research gives us hope for improving not just the performance of implants and hearing aids, but the lives of people with hearing disabilities everywhere.
The UCL team are using a variety of techniques to investigate the cocktail party problem, including in vivo and in vitro brain recordings, psychophysics and computer modelling and human neurophysiology, using EEG and functional MRI. Many people struggle to hear in the cocktail party environment, particularly those with only one functional ear, who (research shows) are more disturbed by interfering noise and further work is needed to help those with implants.
Given the apparent importance of two ears for isolating specific sounds in noisy places, it is believed the auditory system performs a cross-correlation between the signals coming from both ears and that the brain is capable of analysing the pattern to determine the signal from the desired sound source. The brain has been described as akin to a radio, selecting which channel we should pay attention to from the many it is capable of receiving. The brain may also have its own mechanism for selection, depending on the importance of the sound stimulus.
For example, it may be more important to respond to the shouted watch-out warning if someone is about to spill a drink on your new cocktail dress, rather than concentrate on your conversation or more seriously, to respond to the horn of a car in a busy, noisy street. While bionic ears are transforming life for profoundly deaf people, so far, no implant or technology can completely replicate the capabilities of the human brain and auditory system.
Implant users struggle to pick up speech in noisy environments such as pubs and city streets, continued Vivienne Michael. Future research in this field should aim to understand how to match the electronic signals of a cochlear implant with the brains requirements for listening in noise.
Notes to editors
About Deafness Research UK
Deafness Research UK is the countrys only charity dedicated to finding new cures, treatments and technologies for deaf, hard of hearing and other hearing impaired people.
The charity supports high quality medical research into the prevention, diagnosis and treatment of all forms of hearing impairment including tinnitus.
Deafness Research UK is entirely dependent on voluntary donations, gifts and personal legacies. You can donate online at www.deafnessresearch.org.uk , or call 0207 7833 1733 for further information on how to support the charity.
The Deafness Research UK Information Service provides free information and advice based on the latest scientific evidence and informed by leading experts. The Information Service can be contacted on Freephone 0808 808 2222.
For more information on research into deafness, tinnitus and other hearing conditions, log on to the website at www.deafnessresearch.org.uk where you can access a wide range of information. Alternatively you can e-mail Deafness Research UK at firstname.lastname@example.org
One in seven people in the UK almost nine million people – suffer hearing loss.
Deafness Research UK was founded in 1985 by Lord (Jack) and Lady Ashley of Stoke.
In January 2008, Action for Tinnitus Research (ATR) was linked with Deafness Research UK under a uniting direction order under section 96(6) of the Charities Act 1993.
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Ref: DR-UK0208 Brain Awareness Week 2010