Scientists say they’ve spotted a brain region that selectively emphasizes certain sounds, such as the sound of a familiar voice calling a person’s name.

Researchers from the University of Washington, Seattle, and the University of California, Los Angeles, also said the experimental method they used to detect brain activity associated with a given sound task can also identify the type of computation the brain is performing during the task.

During the study, the researchers used functional magnetic resonance imaging (fMRI) to measure blood flow (an indication of activity) in the brain regions of human volunteers as they listened to a series of phonetic sounds.

Using this approach, the researchers noted that a specific area — the left supramarginal gyrus — was activated when the volunteers heard pairs of phonetic sounds that they perceived were different from one another. That area of the brain did not show significant response when volunteers heard sound pairs they perceived to be the same.

Reporting in the Nov. 21 issue of Neuron, the researchers also found that lower-level auditory regions of the brain or another speech-processing area didn’t show significant response to the distinctive phonetic sound pairs.

(Source: NHIC)