Here's why you can focus on your partner at a noisy cocktail party
Washington, Aug 22 : During a crowded and noisy cocktail party, cutting through the
chatter for understanding a conversation is a gift given to humans, say researchers.
Scientists call this ability to listen to someone speaking while many others are
talking loudly at the same time the cocktail-party-phenomenon and it stems from how the
brain distinguishes the pitch of different voices.
It was thought for a long time that the direction where the sounds came from was the
key to doing this.
Now, the latest study, led by Holger Schulze at the Leibniz-Institute for Neurobiology
in Magdeburg, and the Universities of Ulm, Newcastle and Erlangen have found a neuronal
mechanism in the auditory system that is able to solve the task based on the analysis of
the temporal fine structure of the acoustic scene.
The findings show that different speakers have different temporal fine structure in
their voiced speech and that such signals are represented in different areas of the
auditory cortex according to this different time structure.
By means of a so-called winner-take-all algorithm, one of these representations gains
control over all other representations.
This implies that only the voice of the speaker to whom you wish to listen is still
represented in the auditory cortex and can thus be followed over time.
This predominance of the representation of one speakers voice over the representations
of all other speakers is achieved by long-range inhibitory interactions that are first
described by Schulze and colleagues using functional neurophysiological, pharmacological
and anatomical methods.
The results of the study provide a deeper understanding of how the parcellation of
sensory input into perceptually distinct objects is realized in the brain, and may help to
improve the auditory experience of hearing aid wearers at cocktail parties.
The study is published in PLoS ONE.
--ANI
