I'm getting my ears in tune for the wave of birdsong that's migrating through Pennsylvania, now through the end of May.
It's hard to do. Not only is my song memory a little rusty but the birds all sing at once. Their overlapping sounds can be confusing and there's often a problem with background noise. In parts of Schenley Park the traffic roar from the Parkway East is a real auditory challenge, even for birds.
How do birds pick out the individual songs of their own species amidst the cacophony?
They're able to do it, just like we are, using a technique called the Cocktail Party Effect --- the ability to hear one voice in a noisy environment.
In 2010 scientists tested auditory nerve cells in zebra finches as the birds listened to various sounds, including their own species' song. The tests were conducted in both quiet and noisy environments. In both situations the neurons in the birds' brains lit up in a special way when they heard their own song. Like we do, birds have neurons tuned to filter out background noise.
Because birds' auditory structures are similar to ours, scientists hope this finding will help develop better hearing aids and voice recognition systems.
Meanwhile I'm hoping that, with practice, birdsong will light up my brain in that special way too.
(photo by Chuck Tague)