Dolphins produce sound differently above the water and under the water. Underwater, dolphins use a series of clicks and whistles (known as echolocation) to make sounds and communicate. In air, dolphins make sounds releasing air through their blowholes on top of their head. Dolphins have great muscle control over their blowholes and can alter the sounds by changing the size and shape of the blowhole opening. Dolphins have never been able to look inside a dolphins’ head while it is vocalizing, so there are two theories on how dolphins do it!
The most widely accepted theory is the nasal sac theory, that sounds are produced in 3 sets of air sacs in the dolphins’ heads underneath their blowhole. After a dolphin takes a breath, the air returns from the lungs and into these air sacs, making them inflate. At the opening of each of these air sacs in a nasal plug and air is forced out of the air sacs and over this nasal plug, producing various sounds. You can exemplify this with a simple balloon!
- Fill the balloon with air
- Create different sounds by letting air escape out of the end of the balloon by moving it and stretching it in different ways!