In this episode, we’re exploring the sounds of the ocean—specifically, the sounds made by the biggest animals ever to live: blue whales.
Guest bio: Dallas Taylor
Dallas Taylor is the host and creator of Twenty Thousand Hertz, a lovingly crafted podcast revealing the stories behind the world’s most recognizable and interesting sounds. Dallas is also the Creative Director of Defacto Sound, where he has led thousands of high-profile projects ranging from blockbuster trailers and advertising campaigns to Sundance award-winning films and major television series. Dallas is a sought-after speaker at conferences, a regular contributor to major publications, and a respected thought leader on the narrative power of sound. Follow him @D_LLAS.
Abby: It’s just a few weeks away from spring here, which means that pretty soon our whole neighborhood is going to get SUPER LOUD.
Maggie: Yeah, in the spring the woods behind our house get so loud that sometimes it hurts my ears. But the animals that make the sounds are really tiny for such loud voices.
Abby: They’re little frogs called spring peepers! But we’re going to talk about an animal whose big size and big voice go together on today’s episode of
Maggie and Abby: BIG IF TRUE,
Maggie: Where I, Maggie,
Abby: And I, Abby,
Maggie: explore the truth about big things.
Abby: Today we’re talking about WHALES—and specifically, the sounds they make.
Maggie: So here’s our quiz question to test your knowledge:
Abby: Blue whales make sounds that are so low that humans can barely hear them. The way we measure highness or lowness of sound, or the pitch of sound, is called “frequency,” and the unit we use to measure frequency is called “hertz.” So how many hertz is a blue whale’s sound?
Maggie: A. 50 to 70 Hertz
B. 100 to 150 Hertz
C. 10 to 40 Hertz
D. 5000 to 8000 Hertz
Abby: We’ll tell you the answer near the end of the show! Today we have a really special guest to tell us all about sounds underwater—especially loud sounds like whales! In fact, if you’ve ever checked out our #lunchtimelisten on Instagram, you’ve probably heard our guest’s voice—because his podcast is in our regular rotation.
Taylor: My name is Dallas Taylor. And I host a podcast about sound called Twenty Thousand Hertz.
Maggie: Dallas, thank you for talking to us about sounds in the ocean! Is the ocean silent?
Taylor: No, it’s not. So kind of the whole way that sound works is it needs molecules to like bump into each other. So really, anything that has molecules has some sort of sound element. Now how that interacts with the way we hear it is is is unique because our ears are very much in tune with the air of our Earth. But when you go underwater, it sounds, you know, kind of like if you submerge and then your ears are covered in water. It’s almost like your ears were not designed to really understand the way sound works kind of underwater. And that’s because they’re not for underwater. And so yeah, there’s tons of sounds underwater. It’s just all kind of other creatures who have better hearing devices than we do.
Maggie: What kinds of things make sound underwater?
Taylor: Tons of stuff. There’s the song of, songs of whales that can travel 500 plus miles because the density of water as you can imagine, it’s, you know, it’s like water is heavier than air.
And so therefore that density allows for sound to travel really far so whales can talk to each other from really far away. But there’s other things too.
There’s the clicks and chirps.
One of my favorite underwater sounds is the, is snapping shrimp, the shrimps that, like, snap so loud that it actually produces a shockwave and it breaks the sound barrier when it, when it does that.
Abby: Fun fact: that shrimp is also called the “pistol shrimp,” and the sound it makes when it snaps is so loud that the sound stuns its prey. So it’s basically shooting its prey with sound—and a bubble of air that’s generated when it snaps.
Maggie: And these shrimp are only 4 centimeters long! Small but mighty. But there are other things that make sounds too.
Taylor: So that’s really, like, probably my favorite. But really, anything, you know, like rain hitting the surface of water of the water, or undersea earthquakes, which happen all the time, undersea volcanoes. So those are more of the natural side, but there are also human made sounds and that’s where it gets a little sticky because now you know, if you can imagine these gigantic boats that that you know, get our clothes or whatever from overseas and brings it over here, those boats make a ton of noise. And so those sounds, while we may not hear a ton in the air, that can permeate really far underwater to the point where, like, some whales are avoiding where ships travel. So that’s, that’s one; sometimes, you know, other boats do; submarines, drilling sites.
Some things are intentionally done like underwater sonar, or if they’re trying, if you’re trying to map the bottom of the ocean.
Taylor: And then some are a little less intentional, like kind of boat traffic for goods and oil and stuff like that.
Abby: So why do underwater sounds sound so loud?
Taylor: The first thing: iit travels over four times as fast. And it’s because of that density. Like I have never wanted to do this because this just does not feel like in my instinct to ever do this. But if you put your ear up to like a train track, even though there’s no train around, you can oftentimes hear if a train is coming, just because the density of that steel is so dense that like just the sound just travels like super far in it because of that. So for us underwater sounds are so loud, because we’re just not used to one the way it sounds. Because our ears are not for underwater. And then the other thing is just it’s kind of a cacophony, especially when you’re in open water, or a lake or something like that. Usually, if I’m, if I’m like in a lake, you can hear you go underwater to hear, like, of the, the engines and stuff. But it’s so loud just because I think it’s so out of character for how we’re supposed to listen as humans.
Maggie: We know that blue whales, the largest animal on earth, also make some of the loudest sounds on Earth. Why do blue Whales make sounds?
Taylor: We don’t know for sure. Blue whales do make kind of a wide variety of sounds. Scientists are, like most things, are still trying to figure out exactly what these mean. They, both males and females do make single note calls, but only the males sing and like string multiple notes together.
Taylor: Which just kind of alludes to the idea that they are probably looking to have babies somewhere. And so that’s why they’re singing. The single note things that both males and females do, scientists think that that has to do with foraging for food. But others believe that it’s made. Others have said that they’ve heard it at night when they’re not feeding. So that’s one of those things that there’s still a lot to learn about how whales and lots of animals communicate with each other.
Abby: The whale sound that you’re hearing right now has been sped up by ten times so it’s easier to hear in human hearing range.
Maggie: Why do blue whales need to be so loud?
Taylor: One, they’re so loud just because they’re so enormous. You know, just kind of something that’s giant is gonna make a loud sound. And then the other thing is that to get the communication sometimes 500 plus across the ocean just has to be really, really loud. So I think that that just has to do with just how vast the underwater world is, which is pretty cool. Just you know, we have this overwater world but then the underwater world might as well be its own planet. But yeah, my hunch is just to be able to communicate from really, really far away.
Abby: And they’re really, really loud! They can make sounds that are 188 decibels.
Maggie: What’s a decibel?
Abby: It’s a unit of measurement for loudness. 188 decibels is louder than a jet engine. Those pistol shrimp we talked about make sounds that are 200 decibels. But even though blue whales are incredibly loud, we humans might not be able to appreciate their true noise-making skills.
Abby: So how can we hear what blue whale sounds like? We know that the frequency at which they communicate is so low.
Taylor: We can hear pretty low down there. We can usually hear to down to about 20 hertz. And even below that there’s a good chance we’d feel the vibrations. And so blue whales make sounds in the range of 10 to 40 hertz, which is right at the very bottom of human hearing. Like if you’re diving or something, some divers have mentioned, they’ve been able to feel like this low rumble. When you’re really like that low, you start to feel it more as like a vibration in your body more than anything like imagine a really loud concert or something, or from far away, you just hear it like vibrating those low frequencies.
Maggie: Hey, there’s the answer to our quiz question: blue whales make sounds that are between 10 and 40 Hertz.
Abby: Scientists have noticed that over the past 60 or 70 years, blue whales have made their voices even deeper—and thus their voices are harder to hear, even for other whales. But scientists don’t really know why. Some scientists think that it might be because conservation efforts are working, so whales don’t have to be heard so far away because there are more whales. Because there are more whales! But other scientists think that it could be that sound travels farther in the ocean now because there’s more carbon dioxide in the water. That’s a symptom of climate change.
Maggie: Dallas, thank you so much for talking to us about underwater sounds. This was really fun, and we love your show!
Abby: So listeners, our challenge to you this week is to go listen to an episode of Twenty Thousand Hertz.
Maggie: I recommend 20,000 Decibels under the Sea, which is the episode that inspired our episode today! Or if you want more dramatic sounds, check out Tyrannosaurus FX, which is about dinosaur sounds, or Pew Pew, which is about Star Wars sounds.
Abby: If you listen to Pew Pew, you’ll get to hear more animal sounds, believe it or not! For parents, if you want a little trip down memory lane, I recommend the episodes about Seinfeld and the McDonald’s I’m Lovin’ It jingle.
Maggie: And that’s our show for today! Join us next time for another episode of
Abby and Maggie: Big If True!
Abby: Big If True is produced by me, Abby, and Maggie. Special thanks to our guest today, Dallas Taylor. You can find his show wherever you get your podcasts, or at 20k.org. Thanks also to the various scientific organizations who record and distribute the sounds of the ocean. Remember to subscribe to Big If True so you don’t miss an episode, and thanks for listening!