A good ear: Rats identify specific sounds in noisy environments

November 18, 2008

A study conducted on hundreds of rats could help us understand how the brain identifies specific sounds in a noisy environment. The investigation, soon to be published in the journal Brain, was conducted by Alex Martin of the Université de Montréal Department of Psychology.

"Our ears have thousands of ciliated cells with different sensitivities," says Martin. "These cells identify the frequencies that make up a particular sound, but also the spectrum of different frequencies that blend together. That is why we can identify different instruments playing the same note."

For instance, during a concert, when the sound of the crowd mixes with several instruments, our brain can still identify the specific notes played by the trumpet, the violin or any other instrument in the orchestra. Still, Martin was curious to know the impact of background noise on the spatial sensitivity of auditory neurons.

Martin placed rats in a partially echo-free, sound-proof chamber and simultaneously played two types of sounds: Gaussian sound (containing all frequencies) of 25 decibels and a pure sound (made up of one frequency). He found that auditory neurons respond to a pure sound even if there is background noise.

Indeed, 71 percent of neurons don't change their response rate while 16 percent are excited by the sound and demonstrate increased sensitivity. Only 13 percent of neurons decreased their sensitivity in presence of background noise.

Source: University of Montreal

Explore further: The potato disease that changed the world

Related Stories

The potato disease that changed the world

June 2, 2016

Michael David Martin specializes in analyzing genetic material. He works surrounded by envelopes with plants and pictures of speckled leaves that he is studying at the Norwegian University of Science and Technology's (NTNU) ...

Scientists identify genetic cause for type of deafness

September 3, 2009

A team led by scientists from The Scripps Research Institute has discovered a genetic cause of progressive hearing loss. The findings will help scientists better understand the nature of age-related decline in hearing and ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Cow embryos reveal new type of chromosome chimera

May 27, 2016

I've often wondered what happens between the time an egg is fertilized and the time the ball of cells that it becomes nestles into the uterine lining. It's a period that we know very little about, a black box of developmental ...

Shaving time to test antidotes for nerve agents

February 29, 2016

Imagine you wanted to know how much energy it took to bike up a mountain, but couldn't finish the ride to the peak yourself. So, to get the total energy required, you and a team of friends strap energy meters to your bikes ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.