HONG KONG: Ever wondered how we are able to conduct a conversation at a noisy party?

Researchers from Japan, Canada and Germany have found that it is our left brain that picks out the desired sounds from a cacophony of loud, competing sounds.

"In daily life, we are always exposed to several noises at the same time and we have to pick up important signals, for example, speech sounds, from the background noises," wrote researcher Ryusuke Kakigi from Japan's National Institute for Physiological Sciences.

"We found that the left hemisphere is generally dominant for auditory processing in noisy environments," he wrote in an email response to questions from the news agency.

It is well known that speech signals are processed in the left brain.

But this study, led by Hidehiko Okamoto and Christo Pantev at the University of Muenster in Germany, furthers our understanding of how the human brain is able to zero in on the specific sounds it wants and process them.

In the latest issue of the online journal 'BMC Biology', the scientists said they used neuroimaging and observed neural mechanisms in volunteers who were exposed to different combinations of tests and background sounds.

"Test sounds were played either to the left or to the right ear, while the competing noise was presented either to the same or to the opposite ear," they wrote.

"By monitoring the brain's response to these different sound combinations, the team observed that the left hemisphere was the site of most neural activity associated with processing sounds in a noisy environment."