Editing Brown note (section)

==Physiological effects of low frequency vibration==
{{seealso|Infrasound#Human reactions}}

Air is a very inefficient medium for transferring low frequency vibration from a transducer to the human body.<ref>{{Cite journal |url=http://adsabs.harvard.edu/abs/1977JSV....53..605R |title=Tempest, W. ''Infrasound and low frequency vibration'' (1977). Academic Press Inc. (London) Ltd |bibcode=1977JSV....53..605R |access-date=2007-11-10 |archive-date=2008-02-01 |archive-url=https://web.archive.org/web/20080201123920/http://adsabs.harvard.edu/abs/1977JSV....53..605R |url-status=live |last1=Rood |first1=G. |journal=Journal of Sound and Vibration |year=1977 |volume=53 |issue=4 |page=605 |doi=10.1016/0022-460X(77)90533-8 }}</ref> 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&nbsp;dB were achieved at frequencies of 2–3&nbsp;Hz. Test frequencies ranged from 0.5&nbsp;Hz to 40&nbsp;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 legend|urban myth]].<ref>[https://web.archive.org/web/20071231012618/http://srforums.prosoundweb.com/index.php/mv/tree/27986/261708/72/ ProSoundWeb: ''some effects of low end''] (bulletin board entry by [[Tom Danley]])</ref><ref>[https://web.archive.org/web/20080113051923/http://www.danleysoundlabs.com/matterhorn.htm ''The Matterhorn'']</ref>