Happy Meows: Decoding Feline Whisker Sounds
According to the daily observations of cat owners, it seems that cats emit purrs when they are in a state of happiness. But does the purring of cats truly just signify their contentment? People have made numerous guesses, yet there is still no definitive answer. Surprisingly, cats may also purr when they are hungry, injured, or afraid. What is even more astonishing is that research has shown that the frequency of purring can stimulate bone regeneration. That's right; it can help repair bones! So, could placing a few cats next to a patient with a fractured bone and having them purr together also accelerate the healing process for human bones?
Theoretically, this might be possible. However, before we delve deeper, we need to understand how a cat's purr is produced. Cats produce purrs through the contraction of the diaphragmatic muscles during both inhalation and exhalation. Yet, the central nervous system's role in generating and controlling this contraction remains a mystery.
The diaphragm, the partition between the chest and abdominal cavities, was used by early 19thcentury taxonomists to classify feline species. They believed that cats either roar or purr, using this as a criterion for classification, and divided the feline family into the "Purrists" (Felinae) and the "Roarists" (Pantherinae).
However, today's taxonomists believe that, with the exception of a few Pantherinae animals—lions, leopards, jaguars, snow leopards, and clouded leopards (though this is not certain)—most feline species can purr. But why do cats purr? If it is a form of communication, it is likely intended for close, intimate companions. After all, the frequency and volume of a cat's purr are low, making it impossible for the sound to travel far. Purring, along with many other lowfrequency sounds in mammals, often occurs in positive social situations, such as nursing, grooming, resting, and showing affection.
However, cats may also purr when they are stressed, suggesting that it might be a form of selfsoothing or calming, much like humans use crying and laughter to comfort themselves. Some veterinarians and cat owners have observed that cats will lie next to an injured companion and purr, although there is a lack of scientific literature on this subject.
"Purr therapy" can not only soothe injured cats but may also have the potential to heal bones. Domestic cats purr at an approximate frequency of 26 Hz, which falls within the range that can promote tissue regeneration. It's not as exaggerated as it sounds: highintensity exercise also promotes bone health for the same reason. In the wild, cats spend much of their time crouching and waiting for an opportunity to hunt.
Therefore, purring might stimulate bones, preventing them from becoming weak or brittle. In fact, similar vibration devices have been patented for potential use in treatment, and some researchers have suggested attaching vibrating metal plates to astronauts' feet during space travel to maintain bone density.
Is there a business opportunity here? The reasons behind purring are not mutually exclusive. "All behaviors depend on history, environment, and expectation," says Tony Buffington, a feline expert and veterinarian at Ohio State University. "Therefore, to think that cats purr for only one reason is a naive idea, just as it would be to think that humans laugh for only one reason." Humans laugh for joy, out of politeness, in surprise, in disapproval, or even in sarcasm. Only by understanding the specific context can we determine why someone is laughing.
If you want to understand why your beloved cat is purring, Buffington suggests observing what triggers the purr and what the cat does after it purrs. For instance, if your cat greets you with purrs and leg rubs when you come home, it might be thrilled to see you. If your cat constantly purrs around you during dinner, it might be hungry. However, I personally lean more towards the therapeutic aspect, as I find it comforting to hum a little when I'm sick.
