Hi, my name is Steve.
I take care of birds for a living.
You might be wondering why I have a cone in my ear.
It's because we're going to be talking about bird hearing.
On a frequency basis, you can hear more different sounds than an average bird can, but we're
going to talk about the different ways birds have adapted their hearing to their particular
needs.
Wait, birds have ears?
Birds do have ears!
Their ears are mostly inside their head, but you can see the opening out to the outside.
It's easy to see the ear location on a vulture.
Ears are below and behind the eye.
Sometimes the ear is visible as a thin patch of feathers.
Sometimes the feathers are smooth, but the ear is still there.
Which raises an interesting question: how do birds hear?
Imagine trying to hear with feathers on your ears!
It seems impossible, but birds have a neat trick.
The feathers over their ears are thinner and have fewer barbs so that sound can pass through
unimpeded.
Not only that, but the feathers block wind noise while they're flying!
Here's what a bird might hear if the wind hits its ear from the wrong angle.
[Loud wind noise]
You're not going to hear much with that racket going on!
On the other hand, if we put something soft in front of the microphone...
[Softer wind noise]
much better.
Sensitivity Most birds hear best in the range of 1 to
4 kilohertz, but can hear as low as 100 hertz (for a chicken), or as high as 12 kilohertz
(for an owl).
Humans can hear from 30 hertz to 20 kilohertz, with a peak at 2 to 5 kilohertz.
Unless they're old, or went to too many rock concerts, in which case you can knock off
the top 5 kilohertz.
The bird with the best hearing is the owl.
They can hear quieter sounds than humans.
Some, like barn owls, have facial discs of feathers that focus sound towards their ears.
You can amplify your hearing using a simple cone made out of paper.
Just make the end about as wide as your thumb.
Then you can put it over your ear.
I'm going to put it over the microphone so you can hear what the amplification sounds
like.
[Paper rustling, bird sounds]
[Amplified goose honking]
Resolution One more thing about bird hearing, and this
is way cool.
You can process a sound that's about 1/20 of a second, about this long. [chirp]
But birds' brains can process sound much faster, and they can process a sound that's just 1/200
of a second!
So you might hear...
[Nightingale song at normal speed]
Where a bird hears...
[Nightingale song slowed down]
Here's another example.
Here's a human whistling...
[Person whistling "Jingle Bells"]
And then here's a human whistling four times faster.
[Barely recognizable whistling of "Jingle Bells"]
Birds can process sound up to ten times faster than we can, so they could hear the individual
notes in that whole song.
So now you've HEARD a few facts about bird hearing.
I hope you'll share them LOUD and proud.
And subscribe, if that SOUNDS good to you.