The Pond
Pick a place to explore. Tap any picture.
This is the lab where sound turns into a picture you can read.
What each button does
- Draw the Sound lets you tap any frog, hear it, and watch its call get drawn.
- Hear it again replays whichever frog you last picked.
- The two tags under the picture show that frog's length and its pitch in hertz.
- The ruler on the left is pitch. Zero hertz sits at the bottom and 5000 hertz at the top, so a deep voice paints low and a high voice paints high. The ruler along the bottom is seconds, so you can see how long the call lasts.
- Match the Picture shows you a spectrogram with the sound turned off. Read the picture, pick the frog, then press Hear It Now to check yourself.
- Hertz counts how many times a sound wiggles each second. More wiggles means a higher voice.
Pick a frog. Watch its sound get drawn.
A spectrogram is a picture of a sound. Time runs left to right. Low notes sit low. High notes sit high.
Tap a frog above to start.
Whose picture is this?
Read the picture first. No sound until you answer.
Each row is a frog. Each column is a beat. Tap a square to make that frog sing on that beat, then press Play to hear your chorus.
What each button does
- Play starts your chorus and keeps looping it. Press it again to stop.
- Shuffle drops in a random pattern so you have something to start from.
- Clear empties the whole grid so you can build your own.
- Speed is the slider on the right. It sets how fast the beats go, counted in beats per minute. Slide left for a slow, sleepy pond. Slide right for a busy one.
- Peeper Pond, Bullfrog Blues, and February Thaw are three ready-made choruses. Each one is what a Tennessee pond might sound like at a different time of year. Load one, listen, then change any square you want.
- The picture under the grid is your chorus drawn as a spectrogram. Deep voices paint near the bottom. High voices paint near the top, and the numbers along the bottom are seconds.
Top frogs sing low. Bottom frogs sing high.
Low notes sit at the bottom, high notes at the top.
A hidden frog sings. Listen, then tap the frog you think made that sound.
What each button does
- Play the sound plays the hidden frog. The sound waits for you, so nothing plays until you tap it. Tap it again to hear the call as many times as you need.
- Stop ends the sound right away.
- New frog picks a different mystery caller.
- Right, Tries, and Streak keep your score. Streak counts how many you got correct in a row.
- After you answer, the frog's name appears along with what people say its call sounds like and a picture of that sound.
Who is singing?
Two hidden frogs each sing one time. Tap the one you think has the bigger body.
What each button does
- Hear it plays that one frog again so you can compare.
- Two new frogs starts a fresh round.
- Right, Tries, and Streak keep your score.
- After you answer, both frogs are revealed with their real length in inches and their pitch in hertz.
- The chart plots all eight frogs by length and pitch. The dots slide downhill as the frogs get bigger, which is the whole rule in one picture.
Which frog is bigger?
Big frogs sing low
This is the field guide. Tap any frog to hear it sing.
What each button does
- The words in quotes are how people describe that call out loud, like a banjo pluck or a duck quack.
- The inches tell you how long the frog gets from nose to rump.
- The hertz number is the pitch. Hertz counts how many times a sound wiggles each second. A small number means a deep voice.
- The green stripe is the call drawn as a picture, so you can see the sound as well as hear it. The numbers under it are seconds, so you can compare how long each call lasts.
- The frogs are drawn to scale with each other, so the bullfrog really is that much bigger than the peeper.
For the teacher
- Open on the pond. Play four calls in Frogs. Students write the word they hear.
- Who Is It? as a class. Teams hold up fingers for the answer.
- Big or Small, six rounds. Ask them the rule before you show the chart.
- Band. Teams build a chorus, then read their own spectrogram out loud.
- Science Lab. Draw the Sound for two frogs, one low and one high. Then play Match the Picture for five rounds. Students read the picture before they hear it.
- Exit ticket: a frog you never saw sings very low. How big is it, and why?
Frog calls are built in the browser, not recordings. Species from the CRESO Frogs of Anderson County guide.
About the Pond
Eight Tennessee frogs. One very loud spring night.
Poke the peeper. It sings.Every sound here is built, not recorded.
The computer makes each call from scratch out of math, the same way a keyboard makes music. That is why you hear no wind, no traffic, and no other frogs in the background. Real pond recordings are messy. These are clean on purpose, so you can hear one frog at a time.
A spectrogram is a picture of a sound.
Time runs left to right. Low notes sit near the bottom. High notes climb toward the top. Once you can read one, you can tell frogs apart with your eyes instead of your ears.
Big body, low voice.
A bullfrog is about five inches long and sings near 200 Hz. A spring peeper weighs about as much as a paper clip and sings near 2900 Hz. Same rule as a cello next to a violin. The bigger the instrument, the lower the note.
These eight are real Tennessee neighbors.
Every frog here lives in East Tennessee. Their lengths and their calls come from the CRESO Frogs of Anderson County guide.
One of them has gone quiet.
Nobody has heard a Northern Cricket Frog around Oak Ridge since the early 1980s. It stayed in the pond anyway, so you know what to listen for if one ever calls again.