The cocktail party effect: How the brain filters noise

The brain filters noise. This is called the cocktail party effect

Our left side of the brain is more active when we discriminate relevant sounds from background noise, according to the findings of a study by an international team of scientists. The result is the so called cocktail party effect. A night out is often a frustrating experience for hearing impaired people. They find the words of their conversation partners drowned out by the conversations of others, music or street noise. They lack the ability of people with normal hearing to separate relevant sounds from background noise - the cocktail party effect.

Left side of brain sorts out the sounds

Brain researchers have investigated what happens in the brain when discriminating between the sounds we listen for and other noise. The study was headed by Hideko Okamoto of the University of Münster, Germany. He and his team exposed a number of individuals to test sounds and background noise in one or both ears while monitoring their brain activity. The recorded brain activity indicated greater activity in the left half of the brain when discriminating sounds from noise. In other words, the cocktail party effect occurs in the left side of the brain.

As of yet, the researchers are unable to determine why hearing impaired people's ability to discriminate sounds from noise is diminished and reduce the cocktail party effect. This is a matter for future research.

Knowledge about the brain functions including the cocktail party effect will eventually benefit hearing impaired people in terms of the development of new treatment methods and assistive devices and help them to keep the cocktail party effect.

Source: BMC Biology