Scientists explain how purring sounds from cats are similar to roars of larger felines

Cats purring is one of the most refreshing sounds a cat lover can hear. While some consider it noise, for others, it is an enchanting sound to add to their ambiance. The felines just lay there, completely relaxed and unbothered, letting out a purring sound that many even find adorable. Have you ever wondered what causes that sound? Well, a few scientists did some research and came up with a stunning discovery. Current Biology shared the reasons behind the purring echo that defines feline creatures. The article compared the purring to that of the big cats in the feline family and explained the difference.

As opposed to the bigger animals who roar, cats produce a lighter and softer sound, which is more homely and entertaining. The reason behind this is the different structure of the vocal folds. Roaring is the result of elongated vocal tracts that produce higher frequencies. On the other hand, cats have vocal cords, producing shorter frequencies owing to their purring, which is softer and more hushed. The article also mentioned that the fibrous pads in their vocals add fatty tissue, enabling the felines to elicit a low-sounding pur.

What is stunning is that the frequency, as discovered by scientists, is around 20 to 30 Hertz and is very unlikely for animals weighing barely a few pounds. Science.org reports that high frequencies are seen only in larger animals like elephants. It is quite mighty of them to pull up what one assumes is simply an adorable sound. Perhaps it is stunts like these that cause them to be the sophisticated creatures that they are. The brain passes a signal which presses together the vocal cords and when the air flows through the larynx, these cords are knocked together several times to produce sounds heard from the furry felines.

Scientists challenged the idea that the purring was a result of a brain signal and so, via an experiment, they came up with new findings. The article reported that the larynges of eight domestic cats were removed, all of which had been humanely euthanized due to terminal disease, and were investigated with the full consent of their owners. The scientists then pinched together vocal cords and passed humidified air through. The idea was to elicit a sound by isolating the larynx without any muscle or brain signals. Right enough, a sound made its way through.

A "great surprise," says lead author Christian Herbst, a voice scientist. The article reported that all eight larynges produced the sound, highlighting that the brain signal is not a deciding factor that controls the sound of the cats. BBC World Service shared a video on Instagram about the theory and cat owners were glad to know. The caption read, "The low-pitched purr is quite unusual for an animal of that size. But cats have a special tool up their sleeve (or, well, in their vocal folds) that allows them to do it." Cat lovers agreed to this discovery, given the classy and high-end nature cats possess. However, they were intrigued. @arielleshorr said, "Love that we humans have decided to research this."