Is there a better sound than the purring of a cat? For cat lovers certainly not. Cats purr when they feel good – and that good feeling is transferred to their owner. But did you know that cats purr when they suffer from injuries and stress? Why cats do that and how they make the ongoing sonorous buzzing.
Purring is like smiling
A smile stands for satisfaction and well-being. It promotes social interaction by creating an open and trusting atmosphere and creating a sense of well-being and good humor – both with the other person as well as with the smiling one. Quite similar is the purring of our feline friends. Our beloved cats purr when they are stroked and when they doze in bed right next to its owner, exactly like when their mother nurses them, when they get fed, when they encounter a con-specific or when they groom each other. In short, cats purr when they feel good. Still, purring is more than just an expression of comfort – and that’s what it has in common with the smile. Also moods like fear overpowering, pain and hunger can sometimes signal the purring. But what is the purpose of the sonorous buzzer in these situations?
Cats have good reasons why they purr
Purring has a calming effect – not only on us humans, but also on the cat itself. Like no other animal, the cat succeeds in calming itself down. Cat mothers purr during birth to regulate the pain of still-blind and deaf kitten spurring, find their way to the teat and thus to security. Dominant cats purr to show an inferior and nervous con-specific that he is allowed to relax. Many frightened wild cats purrs at threat to control them and to calm down. In addition to the pleasant feel-good purring, there is also the purring for pain relief, reassurance and self-control. Cats also use purrs as a means of communication. Young cats challenge each other to play with purrs, and domestic cats, purring, demand more petting, attention, or food from their people. Why a cat purrs in a certain situation can have different reasons:
- To express well-being
- For stress regulation
- For their own reassurance or of the opposite
- For pain relief
- As a means of communication with each other or with their parents
Purring relaxes and promotes good health
As different as the situations may be, the common goal is to find and promote relaxation and well-being. The fact that the purr does not miss this goal can also be proven biologically. Because the deep, lasting buzzing releases serotonin in the cat’s body. Serotonin, popularly also called happiness hormone, is an important messenger substance (neurotransmitter), which positively influences different processes in the nervous system, such as emotions, the central reward system, moods, state of consciousness and pain evaluation. However, as veterinarians, scientists and behavioral researchers have discovered, this is not the only positive effect on the animal’s health. Thus, recent research has shown that purring has yet another medical benefit in injuries.
Purring vibration training is a remedy
Purring causes the entire body of the cat to vibrate. These vibrations stimulate the muscles and thus support bone growth, as Prof. Dr. (med) Leo Brunnberg from the Clinic and Polyclinic for Small Pets at the Free University of Berlin found out in his research on the morphology of cats. This puzzling result of the self-healing mechanism of purring also explains the fact that cats rarely have broken bones and, if they do happen, purring heal them very quickly.
In principle, cat purring works in the same way as so-called vibration training, as physicians and physiotherapists have been prescribing for a few years to athletes or other patients with muscle or bone problems. In order to strengthen the bone structure and the muscles lying around it, the human body is also set into vibrations in a frequency range of 15 to 60 hertz. Many physicians consider such a vibration training also for patients with osteoporosis or bone loss as conceivable and useful, because as the purring cat proves to improve the lasting mechanical stimuli that arise through the purr, the stability and density of the bones.
Positive effects for cat owners
So we humans can learn a lot from the self-healing effect of purring and even benefit from it – and this is not only true for people with muscle tension or bone and joint diseases. In addition, the calming whirring noise in our body releases happiness hormones and acts as calming and relaxing on us, as on our four-legged friends. A purring cat on her lap or in bed, not only causes happiness, but also lowers blood pressure, reduces stress symptoms and corrects possible cat owners’ sleep disturbances.
How do cats produce the sonorous purr?
The effect of purring is undoubtedly remarkable – but how do cats manage to create such a constant hum? How do you make your whole body vibrate without being strained or having to breathe? Numerous scientists have already thought about this question – but until today this puzzle is not solved unambiguously. While some researchers believe that laryngeal muscles that dilate and narrow the glottis cause the sounds, others believe that the hard, non-stretchable thyroid connecting the tongue to the cranial bone is responsible for the continuous whimpering sound. Still others suggest that skin flaps are close to the proper vocal cords (“pseudo-vocal cords”), or even the main artery plays a role in the generation of purring. At least the latter seems refuted today. Purring, according to current research, is a resonance effect that is believed to arise when the vocal cords bounce.
Only the cats can really purr
The fact is, cats can purr both when inhaling and exhaling, and thus they differ in a special way from most mammals, because they can – just like us humans – produce sounds only when exhaling. Purring is reserved for the world of cats. In addition to domestic cats, there are also lynxes, ocelots, cougars and cheetahs. Big cats like tigers, leopards or lions, on the other hand, sometimes emit short whistling sounds when exhaling, but they cannot last long.
However, accurate measurements have shown that the even purring of the felids differs slightly during inhalation and exhalation. For example, when you breathe in at a frequency of 27-40 hertz, the purring sound is shorter and louder, while when you breathe out, it is slightly quieter and longer at 16 to 28 hertz. But these subtle nuances are imperceptible to the human ear. We hear the purring sounds of our beloved feline friend as a long-lasting and constant buzzing sound, which the animals can effortlessly hold for several minutes.
Purring wants to be learned
What sounds so easy is in reality associated with great anatomical effort. And even if kitties that are already hours old are purring their way to the mother’s milk, it takes a while for the little ones to sound like her/his parents. But the effort of the adolescents is worthwhile, since purring is extremely helpful for the psyche as well as for muscle and bone structure. Unlike the meow, which cats use only in communication with us humans, so cats use the purr also independent of humans. So a lonely lynx purrs just like the family house cat.
Today already growled?
How nice that despite all our inability to relax the mind and body with self-generated vibrations, we can still benefit from the purring of our domestic cats. Because the soothing purring is not only contagious within a group of cats, but also transfers to us two-legged. A purring cat next to us on the sofa lowers our blood pressure; we become calmer and more relaxed and leave the stress of everyday life behind for a moment.
So, what are you waiting for? On the sofa, take the feline friend on your lap and stroke! You will feel the tension of the day fall and the purrs bring a smile to your lips.