Legend has it that there is a certain frequency of sound, better known as a note, which is so low in tone that when played a person near by could lose control of their bowles or other organs…but mainly their bowles…hence “brown.” There is no specific evidence to suggest that this actually happens, therefore it has been classified as the myth of the brown note.
However….They could be on to something…
Television show tests
MythBusters used twelve Meyer Sound 700-HP subwoofers—a model and quantity that has been employed for major rock concerts. Normal operating frequency range of the selected subwoofer model was 28 Hz to 150 Hz but the 12 enclosures at MythBusters had been specially modified for deeper bass extension. Roger Schwenke and John Meyer directed the Meyer Sound team in devising a special test rig that would produce very high sound levels at infrasonic frequencies. The subwoofers’ tuning ports were blocked and their input cards were altered. The modified cabinets were positioned in an open ring configuration: four stacks of three subwoofers each. Test signals were generated by a SIM 3 audio analyzer, with software modified to produce infrasonic tones. A Brüel & Kjær sound level analyzer, fed with an attenuated signal from a model 4189 measurement microphone, displayed and recorded sound pressure levels. The experimenters on the show tried a series of frequencies as low as 5 Hz, attaining a level of 120 decibels of sound pressure at 9 Hz and up to 153 dB at frequencies above 20 Hz, but the rumored physiological effects did not materialize. The test subjects all reported some physical anxiety and shortness of breath, even a small amount of nausea, but this was dismissed by the participants, noting that sound at that frequency and intensity moves air rapidly in and out of one’s lungs.
Another show, Brainiac: Science Abuse, claimed to have performed an experiment using 22.275 Hz (according to the show’s producers used by Japan’s police and tested by the French military). During the programme, they broadcast the note over the air (and into the living rooms of viewers) in an attempt to cause bowel movements among those who had chosen to stay in the room despite repeated warnings and opportunities to leave. However, sound at this frequency at a significant volume cannot be generated by television speakers, nor by most subwoofers, nor by the cassette-tape boombox used to generate the note for the test subject. They also alleged to have confirmed the myth with a subject, but this subject was out of camera shot for all of the piece except at the very beginning.
Physiological effects of low frequency vibration
Jürgen Altmann of the Dortmund University of Technology, an expert on sonic weapons, says that there is no reliable evidence for nausea and vomiting caused by infrasound.
Loud concert levels of subwoofer arrays have been cited as causing lung collapse in individuals who are very close to the subwoofer, especially for smokers who are particularly tall and thin.
In September 2009, London student Tom Reid died of sudden arrhythmic death syndrome (SADS) after complaining that ‘loud bass notes’ were ‘getting to his heart’. The inquest recorded a verdict of natural causes, although some experts commented that the bass could have acted as a trigger.
Air is a very inefficient medium for transferring low frequency vibration from a transducer to the human body. Mechanical connection of the vibration source to the human body, however, provides a potentially dangerous combination. The U.S. space program, worried about the harmful effects of rocket flight on astronauts, ordered vibration tests that used cockpit seats mounted on vibration tables to transfer “brown note” and other frequencies directly to the human subjects. Very high power levels of 160 dB were achieved at frequencies of 2–3 Hz. Test frequencies ranged from 0.5 Hz to 40 Hz. Test subjects suffered motor ataxia, nausea, visual disturbance, degraded task performance and difficulties in communication. These tests are assumed by researchers to be the nucleus of the current urban myth.
Perhaps the myth of “The Brown Note” is just a myth after all. So have no worries and wip out your sub-woofers and keep playing!