Secret Sounds That Heal

by Paula Peterson, with Elizabeth von Muggenthaler

After reading this article, you may have a new appreciation for your cat.

Elizabeth von Muggenthaler is a research scientist and bio-acoustic specialist who has gone where no man (or woman) has gone before – into the mysterious realm of the healing power of a cat’s purring, the haunting whale-song of the Sumatran rhino, and about the sounds that we feel but never hear. She is also president of Fauna Communication Research Institute, where amazing breakthroughs are being made that may forever change the way we listen to the animals. Elizabeth was truly delightful to speak with. Her love and devotion to animals came through quite clearly during our interview. In fact, she was walking one of her beloved horses throughout most of our conversation and spoke to me from her cell phone.

One of the most remarkable things I experienced when first contacting Elizabeth were some of the sounds that play on her research web site. In particular, I was fascinated with the sounds of the Sumatran Rhinoceros. I had no idea that a Rhinoceros could sound so similar to the sounds of a humpback whale. It was eerie and intriguing at the same time. When I asked her about these sounds, there was a noticeable sadness in her voice. According to Elizabeth, the Sumatran Rhinoceros is the oldest living rhino. They’re called the wooly rhinoceros, and there are only about 200 of them left in the world. Poaching and habitat encroachment have devastated them. They stand about four feet tall – no higher than your shoulder – so they’re small and furry, and they sing like whales. These Rhinos are near and dear to Elizabeth. It’s easy to tell that she loves them.

There is a unique parallel between rhino’s and whales

When she went on to study the analysis of the sound recordings of these rhinos, she realized that she had seen this type of signal before. Help came from Jim Darling, who is one of the foremost authorities on humpback whales and has done a lot of research on their song. He sent her a tape of the sounds of the humpback whale, and indeed, there were amazing similarities. Under analysis, allowing for the fact that one animal is underwater, the signal analysis of the sounds is very close.

Elizabeth actually calls their continuous sounds “whale song,” and within those sounds are little “eeps” and other noises, like whistle blows. But the majority of sounds are really very much like whale songs. She spoke with various paleontologists about it. Some said they didn’t know, stating that the whale and the rhinoceros are not considered to be related. However, she did find other paleontologists who held the theory that rhinos and whales are related, and that her research analysis on their song adds support to their theories. Besides, there is something called an ancestral song. It’s never been formulated into a scientific fact, but among certain mammals the elements of a basic song are found. Some of it or all of it sounds very much like whale song. The sounds of the Sumatran rhino may be linked to this ancestral song.

In the wild, these rhinos are supposedly solitary and rarely seen together. It’s really curious that such a solitary creature has developed such an extensive repertoire. They like to lie in their mud wallows and sing. Elizabeth believes that it is some sort of meditation. When she watches them, they will stand there singing in their little mud wallow and being really peaceful. She can’t help but feel that while they’re doing this they are somehow singing with the forest and connecting with the Earth. She gets emotional about them and their beauty, reminding me that there are only around 200 left in the world, and not much is being done about that.

It’s heart-breaking that these wonderful creatures may eventually be lost to us. I noticed my reaction to hearing the rhino’s song on her website. I had never heard such a thing. Especially when I heard the loud popping noise, which sounds exactly like a whale forcing air through its blowhole. Elizabeth says that this is the whistle blow the rhinos make, its very low frequency and it carries for miles. They are found only on the Island of Sumatra. There are only eight in captivity. Three or four are in the United States now. They do not do well in captivity. They are protected, however poaching laws are not being enforced because there is no money to fund that. And since he average person has never even heard that they exist, much less heard them sing, there is no public awareness of what’s happening to them.

Sounds we feel but cannot hear

In analyzing the sounds of animals, very specific equipment is used. At Fauna Communications Research Institute, they have developed a unique system that records signal analysis called “Polynesia.” It’s a “virtual instrument program” that can measure anything. It’s an amazing system. Fauna Research also studies sounds that are below the normal range of human hearing – called infrasound. This is so interesting, and most people don’t know about infrasound. An example of infrasound can be seen when you’re in your car stopped at a traffic light, and you look over and see that the car next to you is shaking because the music is so loud. It’s the infrasound that’s making the car shake. It’s below our normal range of hearing.

The range of human hearing is technically, between 20 and 20,000 hertz. Infrasound is below 20 hertz. It’s been documented that one 19-year-old girl could hear at 19 hertz, but the average person – who has been exposed to car noises, loud noises, and maybe a rock concert or two – is probably hard pressed to hear below 30 or 40 hertz. Another example of how infrasound affects people is in car sickness. The reason some one gets car sick is not always that the car is moving. Car sickness is sometimes caused by the car’s vibration – around 4 hertz.

In fact, cars are interesting; you get all kinds of low-frequency vibrations from them – 4 hertz, 7 hertz – that kind of thing. Frequencies of 7 hertz can cause osteoporosis. Low frequencies like 18 hertz can cause dizziness, blackouts, and feelings of terror. There is a theory that some ghost hauntings are actually caused by low-frequency vibrations of around 18 hertz in a building. That’s a fairly common frequency in structures. Tigers roar at around 18 hertz. It doesn’t matter that you can’t see the tiger. Just hearing the sound is pretty terrifying. I had read an article that the roar of a tiger may actually paralyze its victim. Elizabeth says that this hasn’t been proven. Nevertheless, when she and her researchers recorded the exact frequency of the tiger’s range they found that its highest frequency is right around 18 hertz. So theoretically the tiger’s roar could cause temporary paralysis, weakening of the muscles, feelings of terror, coldness, blackouts, and headaches – that kind of thing.

Infrasound can penetrate solid objects like walls and even go through mountains.

How does it do that? To begin with, ultrasound is a short wave. Take a pen and draw waves up and down, up and down, and make them close together. That’s an illustration of an ultrasound wave. This shape and wavelength causes the sounds to bounce off objects. That’s why this sound frequency is used for sonar, and why bats and dolphins use it for eco-location. Low frequency or infrasound is a very long wave. Take your pen and draw a nearly straight line. That’s how an infrasound signal looks. This is why infrasound can travel through buildings, mountains, etc., because the wave of infrasound is a long wave that actually goes between particles and molecules of an object rather than bouncing off them.

An interesting thing happens when the space shuttle takes off: it creates infrasound that travels the earth about seven times before it dissipates. In fact, if you go about 30 miles south of Coco Beach there’s a little place called Satellite Beach where there is a hotel built mostly of glass. If you are in one of those rooms when the space shuttle is taking off, you will see the panes of glass bow inward about two-and-a-half inches! Lots of things create infrasound: wind, building movement, trains going by, planes flying overhead, vehicles on the interstate. Why isn’t there more study in this area?

People have the tendency to believe that if you can’t hear it and see it then no one else can, either. There is a lot of skepticism to this day in the bio-acoustic field. But scientists are becoming a little bit more open minded than they used to be. I was curious to know if human’s were capable of creating infrasound. Elizabeth said that she didn’t know. However, in some of her studies – and this is something she would like to pursue further – that people who practice certain forms of yoga or martial arts use sound to strengthen their muscles. Our chest cavities are perfectly capable of humming at around 25 hertz; they could vibrate at that frequency. Our voice isn’t going to make infrasound, but our chest, diaphragm, and lungs might. If her research could prove that humans can create that frequency, yoga practitioners who use the Om sound might be able to claim scientifically that they were doing healing.

Now we get to the exciting part: the Cat’s Purr

Elizabeth’s research into the cat’s purr has brought her a great deal of support from many sources, including veterinarians. She has also received support from a professor emeritus in England who is known as the “grandfather of bones.” He is the foremost authority on bone density. She doesn’t want to give his name since she doesn’t have his permission. Interestingly, he writes that optimal frequency for bone stimulation is 50 hertz. The dominant and fundamental frequency for three species of cats’ purrs is exactly 25 to 50 hertz: the best frequencies for bone growth and fracture healing. The cat’s purr falls well within the 20 – 50 hertz anabolic range, and extends up to 140 hertz. All members of the cat family except cheetahs have a dominant or strong harmonic at 50 hertz. The harmonics of three cat species fall exactly on or within 2 points of 120 hertz, a frequency which has been found to repair tendons.

A few veterinarians have said that the purr is only a vocalization of contentment, and most people believe that. But Elizabeth’s research analysis shows it’s not true. Cats will purr when they are injured and in pain as well as when they are content. In one case, a cat had broken its femur and the femur was sticking out. But it was purring, so it can be assumed that purring is not always a sign of contentment. Some people claim that cats purr when they’re injured because they’re humming to make themselves feel better. That makes absolutely no sense. If you’ve ever broken your leg or an arm and you find yourself in the emergency room, are you whistling “Dixie”? Purring takes a lot of energy. It’s created by both the diaphragm and the larynx. Getting a diaphragm to move for something other than breathing is difficult, it takes energy. When there is pain and suffering, our bodies are traumatized and they shut down non-essential activity. Since cats purr when they are severely injured or dying, it has to be survival-related.

Put a cat in a room with a bunch of broken bones – the bones will heal

According to Elizabeth, that statement is an old veterinarian’s adage and it’s still taught in veterinary schools to this day. That’s the first thing she came across when she started out with this research. But no one has done any studies on it. The type of frequencies that are found in the cat’s purr are good for healing muscle, tendon, and ligament injuries, as well as for muscle strengthening and toning. They are good for any type of joint injury, wound healing, reduction of infection and swelling, pain relief, and relief of chronic pulmonary disease.

Authors of the veterinarians’ surgery manual say that what it basically comes down to is that, compared to other animals, cats simply don’t get chronic pulmonary disease, muscle and tendon injuries, bone diseases, and a lot of other things that dogs get. The purr seems to be a constant strengthener and toner for the muscles. The average health of cats is considered to be greater than that of dogs. An actual case study was done where they took 52,000 animals and found that lameness in dogs occurred 3.6 percent and in cats only .26 percent. In another study, arthritis in dogs was listed as 2.4 percent of the population, and was not reported at all in cats. The prevalence of lameness in dogs occurred 3.1 percent of the time, and again, in cats it was not even mentioned. The overall incidence of primary lung tumors in the dog is 1.24 percent, and in the cat, .38 percent. This basically says that cats are in fact healthier than dogs are.

People like to say, “Oh, that’s just coincidence,” but it can’t be. The odds of its being coincidence are like three billion to one. Any veterinary orthopedic surgeon will tell you how relatively easy it is to mend broken cat bones compared with dog bones. Dog bones take much more effort to fix and longer to heal. There is excellent documentation of cats’ quick recovery from such things as high-rise syndrome, which was first mentioned by Dr. Gordon Robinson and later studied and reported in the Journal of the American Veterinary Medical Association. They documented 132 cases of cats’ plummeting an average of 5.5 stories from high-rise apartments, with some of them suffering severe injuries. But interestingly, 90 percent of these cats survived. Most cats that fell from seven stories or more managed to live. The record for survival from heights is 45 stories!

Is there a difference between a cat’s purr of contentment and the purr of a cat that’s been injured? Apparently, there is no difference. It’s machine-like. The purr is nearly the same across species: The ocelot, chervil, and domestic cat are all create an identical sound. Elizabeth showed this data to an architectural engineer who measures building vibration, and he asked if she were into mechanics, since the signal appeared to be so regular. He was greatly surprised when she told him that he was looking at the analysis of a cat’s purr. It’s totally unlike any other animal’s vocalization.

An idea is born

Elizabeth stumbled upon these ideas by accident (which is true of most inventions and discoveries!). She had been working with tigers at a facility where there were also many other wild cats. It seemed odd to her, while passing by a chervil one day, that it was purring. Later on, she read in National Geographic about this researcher who had put chickens on a vibrating plank for twenty minutes a day and their bones grew. She thought that was weird. So she called him and asked what the anabolic frequencies for bones were. He said that they were anywhere between 20 and 90 hertz, but that there is evidence suggesting that 25 hertz and 50 hertz are the best frequencies. The next day, she got up, went into the living room, grabbed her big tomcat, Spot, started petting him, and turned on the microphone. Then she ran the recording through the computer. And guess what? Oh, my God.

After that, she started doing a search in the literature, and found that 25 hertz is the fundamental frequency. In other words, it’s the first, or primal, frequency. After the first frequency, there is something called harmonics. Harmonics are always a multiple of the fundamental, meaning that if the fundamental is 25 hertz, the first harmonic is 50, then the second harmonic is 75, the third harmonic is 100, and so forth. She started recording the wild cats. Then she grabbed every domestic cat from her friends and other people. “Excuse me. Can I record your cat?”

Then she took accelerometers and started measuring cats – accelerometers measure vibrations – to find out where on the body the sound is the strongest and weakest. The research revealed that the vibrational signal is at its weakest at the extremities. Interestingly, it’s rare for cats to get bone cancer, but when they do, it’s most often in the distal end of the extremities – the paw – and that’s also where the vibrational signal is the weakest. What are the odds that in six out of seven species of cat, their purrs are identical in frequency and amplitude? All of these cats come from a geological evolution that is different – South America, Africa, Asia. Yet the sounds they make match exactly, in both amplitude and frequency, to the frequencies that have been found to be healing, and not just for healing of bones.

I’ve had healing experiences with my own cats. I had one cat that slept with me every night, and it always felt so good and peaceful to have her next to me. And of course, she purred loud and long until we both fell asleep. So, I wonder, is it helpful for people to hold their purring cat close to their bodies? Elizabeth says that from a scientific standpoint she would have to say she doesn’t know since there is no evidence. She goes on to say that for something to be scientifically therapeutic, it has to be exactly the right strength, loudness, and amplitude. However, she did say that as a healer, she says “yes, it absolutely”, it can be helpful to sleep with you cat. You, yourself, may have noticed that when you’re not feeling well, your cat will often come up to the part of your body that’s aching and start to knead you with their paws, purr and get that meditative look in their eyes. They could be trying to help.

How can we make a difference?

People tend to equate language with intelligence, says Elizabeth, and feels that people would be more willing to give of themselves to our amazing animal friends, both wild and domestic, if they considered them intelligent. We have a lot to learn from them. Most of our modern medicines come from plants or animals. Killing them off is killing us. The average person does not realize that every time an animal becomes extinct we lose another opportunity not only to learn more about our world but also to gain something possibly therapeutic from this animal. It’s unfortunate that many people are so consumed with purchasing expensive possessions that they don’t stop to appreciate what we already have that has been given to us.

As an avid animal lover, I know full well that animals are intelligent beings even if they don’t speak an understandable language – although my own cats have tried to talk like humans. Elizabeth has a recording of a cat in a veterinarian’s office who kept saying its owner’s name. Animals have so much more than we have. As humans, we are limited by what we’re able to see, hear, and smell. Our senses are nowhere near as keen as those of a dog or a cat. You may have seen your own cat at times looking at something you cannot even sense, much less see. Most humans presume that their cats are just staring into space, but they are tracking something.

We as humans can’t even begin to understand what a dog smells. Their noses are many times more efficient than ours. A scallop has a hundred eyes, so it really does see us as we’re ripping it from its home. Birds see in the ultraviolet spectrum. We can’t see that. We’re so limited. It would be nice to spend a day inhabiting the body of several different creatures, just to experience what they’re able to see, feel and hear that we can’t. Well… I could have listened to Elizabeth go on and on – her work is that interesting – and she was quite pleasant and easy to talk with.

To find out more about Elizabeth Von Muggenthaler’s important research, animal sound recordings, CDs, or how you can help protect the Sumatran rhino from extinction, please visit Fauna Communication Research Institute at:
to hear the unusual sounds of the Sumatran Rhino, click on Research or News.

Author: Paula Peterson, with Elizabeth von Muggenthaler