Learn why the most famous dolphin squeak of all is actually a fraud. This episode looks at one of the most recognizable and famous dolphins sound of all time, and gives an in depth explanation as to why it may not really be a very good example of a dolphin sound at all.
You may recognize this sound [play sound] – it is the ever-popular and greatly over-used dolphin squeak sound that is played whenever a dolphin makes an onscreen appearance for TV or in the movies. But, there is something fundamentally wrong with this sound. True, it was most likely recorded from a real live dolphin, but it is certainly not a typical dolphin sound. Here’s why: dolphins spend their entire lives under water – that’s an amazing place to be if you want to use sound as a form of communication. The speed of sound in water is around 1482 m/s approximately or 4.5 faster than the speed of sound in air: 331.5 m/s. Not only does sound travel faster in water, but it can travel farther. If it is loud enough and at the right frequency, and if the water conditions (like temperature and salinity) are just right, a sound may travel for thousands of kilometers. Given the ideal conditions that an undersea environment provides for sound transmission, it is no surprise that dolphins have evolved to be very vocal animals. Dolphins make a huge variety of sounds underwater, but they can be more or less put into two different categories: whistle; which are frequency-modulated pure tone sounds, and pulsed sounds; that sound like clicks, creaks, or rusty hinges. Generally, whistles are used for communication, and the pulsed sounds are used for echolocation, or dolphin sonar. This isn’t always true, however.
Some click sounds are used for social communication. For example: rapidly-produced, high-intensity clicks called squawks are thought to be used during aggressive encounters – dolphins appear to hit each other with a burst of loud click sounds as a means of hurting their opponent. Kind of like a wild west shoot out, but with sound-waves instead of six-shooters. So what is so wrong with that famous (or perhaps infamous) squeak sound we heard at the beginning of this episode? [play sound] Well, that sound was produced in air, not under water. And that is something that dolphins never usually do. The overplayed Hollywood squeak sound that we are all so familiar with was likely produced for the benefit of human listeners, and is in no way a normal part a dolphin’s natural communication system. Hmm – it seems that dolphins are much more adept at altering their own communication system to communicate with humans that the other way around.
Learn more about the sounds that dolphins and other marine animals make: Discovery of Sound in the Sea