The lion has the loudest roar of all the big cats ... helped by swivelling ears that adjust to the direction that sound is coming from. Their sensitive hearing means they are able to stalk ...

Sounds majestic, right? Just like the famous MGM roar. Here's the issue: A lion's roar doesn't sound like that. This is a roar. It's not quite as majestic as what you hear in the movie ...

Sounds can be high pitched, like the squeak of a mouse. Or low pitched, like the roar of a lion. But what is it that makes these vibrations different? This explorer is wearing special goggles.