DISCLAIMER: I write a disclaimer here because I need to protect myself legally from people who might think that because I have a Ph.D. and can be called “Doctor”, that I somehow can give medical advice. I cannot, and do not. I do, however, have a simple idea that you can take to an open-minded physician. The two of you can then talk about it. Do let me know what happens.
A number of readers have wanted to know why I have not yet dealt with infrasound in a substantive way as it relates to the Hum phenomenon. There are several reasons. First, I am a teacher of science and not a scientist, which means that (apart from my actual areas of academic expertise) I am expected to know a little bit about many scientific topics, and be an expert on none of them. The second reason is time. I’ve invested at least 1000 hours learning new material, scanning abstracts, chatting with working scientists, and sometimes just sitting and speculating, staring into space and waiting for whatever “Eureka” moments might come. A recent exchange with a reader of this blog showed me quite convincingly that I was wrong about a basic rule that many of use when talking about sound. We are taught in school that the typical human hearing range comprises frequencies from 20 Hz up to 20 kHz. Frequencies below 20 Hz are referred to as “infrasound”. What happens at the lower end of that range has been poorly understood and oversimplified until relatively recently. There is no sharp dividing line between sound and infrasound. Try the following experiment: go to an online tone generator, such as http://onlinetonegenerator.com/, and connect your computer or phone to a good set of speakers or headphones that have good bass response. Start at around 60 Hz, and then begin lowering the frequency. You will notice that at some point you feel the sound more than you can hear it. There are many people who report that some tones, down around 17 or 18 Hz, if played with enough power, can cause unusual and sometimes unpleasant sensations. The biological system that processes acoustic signals is massively complex and involves numbers of structures and mechanisms. The person who posted to this blog claimed that he can hear frequencies as low as 1 Hz or even lower. This was met with some derision by a few readers, and I simply dismissed it as a case of somebody who was ill-informed about the science. That was not the case. One reported effect of Meniere’s disease is to render patients sensitive to lower frequency sound and infrasound. The same contributor sent to me several links to infrasound studies. One of those studies (Salt & Lichtenhan, 2014) addresses the issue of wind turbines noise, and suggested an idea that may have big implications for the Hum community. A tympanostomy tube insertion is a common procedure in which a small tube or grommet is inserted into the ear drum so as to prevent fluid buildup and to aerate the middle ear. It happens to be one of the most commonly performed medical procedures on children, as well as being a treatment for Meniere’s disease. It is a simple procedure which can be performed in the doctor’s office under local anesthesia, although with children, general anesthesia is often used to prevent movement during the insertion. The procedure does not affect sensitivity to frequencies of speech and other daily sounds, but it drastically reduces sensitivity to lower frequency sounds. The authors suggest that this procedure could provide relief from sensitivity to infrasound. And so, I took all their work and moved it a few inches down the road by suggesting that this may be a medical treatment for the Hum. Again, I give no medical advice here, but if you do pursue this with your doctor, I’m sure there are many people who will very much want to know what the results are.