Our brains filter out the noise we make as we move so that we can focus on the environment around us. (Free-Photos/Pixabay)

BOB HIRSHON (host):

A noise-canceling brain trick. I’m Bob Hirshon and this is Science Update.

(sound of footsteps fading out to singing birds)

We make noise when we move, but our brains filter out much of it so we can focus on the environment around us.

DAVID SCHNEIDER (Duke University/New York University):

I only want to ignore those acoustic features produced by my footsteps.

HIRSHON:

Duke University neurobiologist David Schneider and his colleagues conducted experiments with mice revealing that during movement, the motor cortex of the brain sends signals to the auditory cortex telling it to disregard the sounds made by those movements.

SCHNEIDER:

And then what I’m left with is all the sounds I didn’t make, and those are the sounds I can process and react to. If a mouse can ignore his own footsteps he can maybe detect a cat that’s out there stalking him.

HIRSHON:

Schneider says that our brains may use this noise canceling trick, too, constantly adapting to the variety of sounds we ourselves make. The study appears in the journal Nature. I’m Bob Hirshon,  for AAAS, the science society.

Footsteps Sound  (https://freesound.org)

Birdsong Sound (https://freesound.org)

Attribution 3.0 Unported (CC BY 3.0)

Story by Susanne Bard