Photo credit: Froggydarb licensed under CC BY-SA 3.0
by Jan L. Mayes, MSc, Audiologist (Retired)
Ever had trouble understanding what somebody was saying in a noisy background? Frogs have a similar problem hearing mating calls when all the pond frogs are chorusing. Using 15 years of data from the North American Amphibian Monitoring Program, researchers discovered frogs have a built-in solution: their lungs act like noice-cancelling headphones to hone in on calls from same-species suitors.
There are natural differences in vocal frequencies between species. When frogs inflate their lungs, it cuts eardrum sensitivity across specific pitch ranges. This makes it easier to hear mating calls from their species while screening out calls by other frogs.
The scientists believe this physical mechanism of spectral contrast enhancement is similar to how noise-cancelling headphones work. It’s also similar to signal processing algorithms in hearing aids or cochlear implants where sound outside the main speech range is filtered out to lower noise interference.
One day humans will be back to gathering in groups, and having trouble understanding spoken conversations when there’s too much ambient environmental noise. Too bad we can’t inflate our lungs to cancel noise instead of waiting on decision makers to take noise prevention action.
Jan L. Mayes is an international Eric Hoffer Award winning author in Non-Fiction Health. She is also a blogger and newly retired audiologist still specializing in noise, tinnitus-hyperacusis, and hearing health education. You can read more of Jan’s work at her site, www.janlmayes.com.
