Audiologists don't have to be bird watchers. But bird watchers do have to be hearing specialists!
Hearing is an amazing ability that we share with the birds. They fly away if watchers are too loud. But if birdwatchers stand still and listen, their ears receive waves of energy that started as air puffed out by a bird. The energy moves molecules in waves of a particular height, speed, and length to be perceived by the birdwatcher as a particular specie of bird.
When a bird sings out a song, birdwatchers cup hands around ears to catch the energy waves that funnel in for analysis by the brain. In the seasons of the year when leaves conceal most birds that perch in trees, birdwatchers have to pay special attention to bird calls. Birdwatchers often hear a target bird long before binoculars are focused on them, if at all.
Bird calls illustrate some qualities of sound. Click on the bird names below to play its songs that illustrate sound qualities.
High-pitched Bird Call
Birders with especially good ears hear the signature high-pitched notes that start the song of the Ruby-crowned Kinglet long before he chatters through the rest of his call. The remainder of its call is accented with a few more treble sounds.
Low-pitched Bird Song
The Mourning Dove’s mournful call is sung at a lower pitch than most of the other birds that gather round the feeder. His call starts as a bass note, hops up about 7 steps, and back about 1 step for three more beats.
Loud Bird Call
The Carolina Wren is known in the Eastern United States as the loudest bird in the forest. He sings a song made up of a series of beautiful pure tones. Birdwatchers remember his call because it sounds like he is saying “tea-kettle, tea-kettle, tea-kettle” or “Germany, Germany, Germany.”
Periodic Sounds from the Birds
In the summer months we see the Green-winged Teal on the waterways in the Chesapeake Bay area of Virginia. The waterfowl sings out a series of short whistle, each of which might be considered as periodic sounds, where the wave frequency and height are continuous and repeated.
Aperiodic
The Great Blue Heron’s call is noisy. While every tone isn’t unpleasant, most will agree that he leaves a bad impression. When several Great Blue Herons are startled and fly away at one time, they create a truly cover-your-ears-quick aperiodic racket. A aperiodic sound is distinguished by its inconsistency or the sort that most would classify as noise.
Pure tones
The Hermit Thrush has a call made up of 3 patterns that are approximately the same but sung each at a different pitch. For a second or two at the beginning of each pattern, the first note is a pure, consistent tone sung out loud and clear.
Complex Sounds
The Goldfinch is a beautiful yellow and black bird and you never see just one as they search out seeds and nectar in stands of wildflowers and grasses. Since they usually are seen a half dozen or more at a time in the springtime, just imagine the complex overlay of tones you might hear from them at any given moment.
The array of pitches from high to low, treble to bass, mixes and mingles all day to create the favorite pressure wave that are translated by in the brains of birdwatchers to help them hear and identify each species of bird. The Cornell Lab of Ornithology’s website includes a page that describes more interesting bird sound. It includes audio files that emit energy waves to be heard and spectrograms to show the sound patterns of calls.
Sara E. Lewis - Sara E. Lewis is a writer and publications consultant. As a freelancer, she writes and produces marketing materials and especially enjoys ...
