Human brain recognises new sounds better

Our brains register new and approaching sounds much better than noting the disappearance of an existing one, says a new study.

The research, funded by Wellcome Trust, could explain why parents often fail to notice the sudden quiet from the playroom that usually accompanies the bustle of mischief. Hearing plays an important role as an early warning system to rapidly direct our attention to new events.

Indeed, we often rely on sounds to alert us to things that are happening around us before we see them, for example somebody walking into the room while our back is turned to the door, the journal Public Library Of Science ONE reports.

Yet, little is known about how our brains make sense of sounds around us and what makes us hear certain events while completely missing others.

Researchers at the University College London Ear Institute wanted to understand what makes certain sounds easily detectable while others go unnoticed. They created artificial ‘soundscapes’ comprising different ongoing sounds and asked listeners to detect the onset or disappearance of different sound objects within the melee, according to University College statement.

Overall, the team found that listeners are remarkably tuned to detecting new sounds around them but are much less able to detect when a sound disappears. In busy sound environments, the participants missed more than half of the changes occurring around them and the changes that were detected involved much longer reaction times.

Maria Chait, who led the research at the Ear Institute, said: “On the one hand, we might expect to be more sensitive to the appearance of new events. In terms of survival, it is clearly much more important to detect the arrival of a predator than one that has just disappeared.

“Understanding what makes certain events pop out and grab attention while others pass by un-noticed is important not only for understanding how we perceive the world but also has important practical applications,” added Chait.