Hello! It’s me, Boop! I’m the Discovery World spokesturtle! Beep and I are doing well. We hope you are well as well.
Good news, everyone! We are working on a plan to reopen! And by “we”, I mean the people here who make these kinds of plans and decisions, not Beep and me. If it were up to us turtles, we’d open Discovery World tomorrow. Beep and I really miss you!
It’s probably better that decisions like this are not up to us turtles. Turtles make plans and decisions all the time of course, but they’re typically more about which pieces of lettuce to eat first. Those kinds of decisions don’t exactly, uh, scale up? Sure. Regardless, Discovery World is not opening tomorrow.
Last week, Beep and I made a Time Machine. It went okay. This week, Beep and I are taking piano lessons! It’s super fun. We’re not taking formal lessons. Beep and I sneak up to the Pilot House whenever we can and bang around on the piano up there. That’s almost the same as formal lessons, probably.
The first time that Beep and I discovered the piano, we thought that it was broken. The middle of the keyboard worked great, but there was no sound on the left or right sides of the keyboard. We were banging and pounding and wailing away on those keys as hard as we could, but we couldn’t hear anything.
Then the Aquarists found us. We couldn’t figure out how they found us because we were being super quiet. It turns that we were not being super quiet (or any kind of quiet), and the piano works just fine. Turtle’s don’t have very good hearing. I did not know that. Other animals have really great hearing. Turtles not so much.
Did you know that elephants can hear clouds forming? That’s amazing. I can’t hear clouds forming. I didn’t even know that clouds made noise. I wonder what else makes a noise that I don’t know about. I don’t even know what I can’t hear, because how would I know, you know?
It’s like trying to smell with your knees, maybe. If your knees could smell a few things but not most things. Can you smell with your knees? I can’t smell with my knees. Catfish can taste stuff with their skin and stingrays can sense electrical fields, so it’s not an entirely silly question. Also, I don’t know all there is to know about humans. Where was I? Oh, right.
Noise. Sound. Hearing. As you already know, sound is mechanical energy, pressure waves that travel through the air and into your ears. I assume those big sticky-out things on the sides of your head are ears. Those are your ears, right? Sorry, was that rude? And did I say big? I meant adorable. Turtles have ears, too! You can’t see my ears. Turtle have internal ears.
Turtle ears transform the mechanical energy of sounds waves into electrical signals. Our brains interpret those electrical signals as noises and sounds. Your ears transform mechanical energy into electrical signals, and your brain interprets those electrical signals as noises and sounds and language and music and all the other wonderful things that you can hear.
Sound waves have amplitudes and frequencies. The greater the amplitude, the louder the sound.
The frequency of a sound is the number of vibrations or cycles per second. The greater the frequency, the higher the pitch. The lower the frequency, the lower the pitch. Frequency is measured in something called Hertz (Hz). On a piano, Middle C (C4) has a frequency of 261.6 Hz. Concert A (A4) has a frequency of 440 Hz. That’s not the interesting part.
The interesting part is that turtles can only hear frequencies from around 200 Hz to 750 Hz. That’s a range of less than two octaves. I can hear Middle C and Concert A, but I can’t hear most of the piano keys. The lowest note on a piano with 88 keys is A0. It has a frequency of 25.7 Hz. I can’t hear that at all. I can feel the vibrations, but I can’t hear it. The highest note on a piano is C8 at 4186 Hz. That’s way beyond what I can hear.
That’s why Beep and I thought the piano was broken! It’s also how the Aquarists found us. We thought we were being stealthy, but instead we were being really loud. We had no idea!
You humans can hear sounds with a frequency from 20 Hz (lower than the lowest note on a piano) all the way to 20,000 Hz. You have a hearing range of around 10 octaves! What does the world even sound like to you? I can’t even imagine!
Elephants can hear sounds as low as 12 cycles per second and as high as 12,000 cycles per second. That’s around 10 octaves. Your dog has a hearing range of roughly 67 Hz to 45,000 Hz. That’s just under ten octaves.
Your dog has pretty much the same range of hearing as you do, but your dog can hear ultrasonic frequencies. You can’t. Of course, the only reason you call those frequencies ultrasonic is that they’re above the threshold of what you can hear. Infrasonic frequencies are below what you can hear. What’s ultrasonic to you is plain old sonic to your dog. And what’s infrasonic to you is regular sonic to an elephant.
A lot of what’s sonic to you is ultrasonic to me. And a lot of what’s sonic to you is infrasonic to me. That’s okay. I smell better than you do. I mean, I have a better sense of smell than you do, not that I smell better than you. I don’t know how you smell. You probably smell very nice.
Your hearing is pretty great, though. Porpoise hearing is even better. They can hear from 75 Hz (D2 on the piano) all the way to 153,000 Hz. That’s around 11 octaves!
Bats (though it varies a lot by species) can hear sounds from around 9,000 Hz to 250,000 Hz.
Some moths can hear the high-frequency echolocation chirps of bats. That seems pretty useful, especially if you spend a good deal of your evening trying not to get eaten by bats. Some moths send out their own high-frequency chirps that disrupt bat echolocation. I had no idea moths were so clever.
There are so many sounds out there that I’ve never heard, that I don’t even know about. What’s your favorite sound? What sound would you most like to hear, if you could?
Anyway, the wonderful Aquarists here are super-supportive of my piano playing. My first recital next week, and I’ll be performing John Cage’s 4’33”. The Aquarists are making sure that I practice it a lot! Over and over and over again, in fact. I’m a little nervous, but I’m sure I’ll do great.