One of the most heartwarming sounds a person can hear is the sound of a cat purring. Cats tend to purr when they are in a content mood, which is often when they are about to fall asleep after a cuddle session. Felines are not only able to put themselves into a sleepy trance when they begin this domestic cat behaviour, but they can also put their human companion into a state of relaxation. In fact, it has been noted that hearing the sound of a cat purring can help to lower a person’s blood pressure, and even ease depression. The healing effect of the purr is one of the many reasons that felines take up residency as therapy animals in hospitals.
How do felines demonstrate this remarkable behaviour?
The answer to this question has been highly debated with several theories arising over the years. Today the most common theory about what causes cats to purr is that it is from air passing through their voice box.
When your feline friend begins to purr the diaphragm in her voice box starts to open and close quite quickly. With the diaphragm twitching at this rapid pace, any air that passes through it begins to vibrate. The vibrations in the air passing through the voice box are what cause the purring sound. In fact, the diaphragm twitches so quickly that felines have the ability to purr from 25-50 times per second. This purring frequency is the same as an idling diesel engine in a vehicle, which is likely why people say that kitties have little motors inside of them.
Have you also noticed that your feline friend continues to breathe the entire time she is purring? Your kitty does not have to stop to catch her breath in between purrs because the air is passing directly through her voice box during both inhales and exhales. This is the air that helps your kitty to purr.
Another interesting fact about this domestic cat behaviour is that some cats purr differently to influence their human companions to do tasks for them, such as to wake up and feed them. The purr that a feline will use to wake up a human has a frequency similar to a baby crying. That sound will definitely get a person out of bed in the morning.
Remember this information the next time you are lucky enough to hear this phenomenal domestic cat behaviour. You may even be able to tell if your feline friend is just being nice or if she is looking for someone to feed her.