Why cats really purr: Beyond the sound of contentment

Are you a cat owner? You have surely wondered why your pet purrs. This sound is most often associated with contentment, but it turns out this isn't the only reason cats make this sound.

Cats are unique creatures. They walk their paths for a reason, being very independent and fiercely defending their boundaries. Despite this, they openly show love or satisfaction, for example, through purring. But this sound also signifies several other things. So, how should we interpret a cat’s purring?

Purring is a characteristic, vibrating sound made by cats. Scientists have pondered for years how domestic cats generate vibrations at such a low frequency, ranging from 20 to 150 hertz.

Experts have examined this phenomenon to discover what purring is all about. A study published in 1970 showed that everything starts in the cat’s brain. After receiving an impulse, within a minute, the cat tightens and relaxes their laryngeal muscles up to 30 times, causing their body to start vibrating.

However, in 2023, a team of scientists led by Christian Herbst debunked this theory. The researchers removed the larynx from the bodies of eight cats that had been euthanized due to terminal illness. After removing the organ, scientists blew warm, moist air into it. Each larynx produced a sound reminiscent of purring. This confirms that cats purr automatically, without any control from the brain or muscles.

Cats never purr without a reason. It is their way of communicating with people and other animals. While it is commonly accepted that purring is a sign of satisfaction, cats also purr in other situations.

They purr when they are comfortable and blissful, and when they want to demand something from us, such as food. Studies have shown that cats purr when they sense their caretaker is sick, stressed, or depressed, because purring has a soothing effect on humans.

This is why cats are used in felinotherapy. Contact with cats lowers blood pressure and anxiety levels, and it stimulates the release of endorphins. Cats also know that purring has pain-relieving effects; an injured or suffering cat will purr to reduce pain.