Air Date: Week of April 13, 2012

Scientists in Germany have created the world’s smallest ear, capable of detecting sound waves six orders of magnitude below the threshold of human hearing. As Living on Earth’s Sophie Golden reports, this nano ear may be able to hear the bacteria in our bodies.

Transcript

GELLERMAN: Coming up – the sage grouse - does it belong on the endangered species list or on the menu of a French bistro? But first this note on emerging science from Sophie Golden.

[MUSIC: SCIENCE NOTE THEME]

GOLDEN: Imagine hearing a bird swallow, or the footsteps of an ant. Well, if scientists in Germany have their way, supersonic hearing may become a reality. Physicists at Ludwig Maximillian's University have developed the world's first nano ear, capable of detecting vibrations six orders of magnitude below the threshold of human hearing.

The microear was created by trapping a nanoparticle of gold in a laser beam. The fleck of gold can't move on its own, but is affected by sound waves. To test the ear, scientists submerged it in a water-based medium and then introduced a variety of sounds. They measured the amount the gold particle moved to pinpoint the frequency and direction of the sound waves. What they discovered is that this tiny piece of gold can detect vibrations of minus 60 decibels.

The physicists hope the nano ear will allow humans to hear live microorganisms, such as bacteria and viruses. So, if your doctor only has to listen to your body to find out what's ailing you, ear scopes and throat swabs may eventually be tools of the past. That's this week's Note on Emerging Science, I'm Sophie Golden.

Links

Article in Physics World