On Mon, 1 Nov 2004, Ron Fletcher wrote: > > Peter wrote... > Did anyone else ever notice that if you play the lute wearing a cowboy > hat-- yes, my fellow Brits, a bowler hat will do too, or for that matter > any hat with a rim-- you have your own private acoustic shell which > allows you to hear your lute better? > > Why yes, I occasionally wear a wide brimmed 17th century felt hat with > an ostrich feather. The brim is turn down slightly to give a gently > dished effect that would collect the sound waves from below. > > Cowboy hats and bowlers curve upward and I assume therefore they would > lose most of this effect. The Panama hat sounds good.
I originally tended to share Ron's intuition that downward curvature would be more efficient, but I'm not sure that this is correct. (This --forgive the geek talk-- because the wavelength of the sound waves exceeds the size of the hat, so that geometrical optics/acoustics approximation, which is used to explain the behavior of lenses and curved mirrors, is invalid. This leaves me with little intuition to go by. It is of course quite possible that the effect is caused by higher harmonics for which the geometrical approximation might be valid.) The bottom line is that I'd like to do the experiment, but unfortunately, the only hats I have, the ones with which I noticed this effect, are of the upside-down bowl type. If anyone out there has a more diverse hat collection and wants to do the experiment, please let us know if you detect a curvature dependence. Peter. > > Odd though that most paintings of lute-players depict men wearing soft > 'Van Dyke' hats? > > Best Wishes > > Ron (UK) > > > > > > To get on or off this list see list information at > http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html > -- the next auto-quote is: Nature is only part of what we can imagine; everything, real or imagined, can be appraised by us, and there is no outside standard to show that our valuation is wrong. (Bertrand Russell) /\/\ Peter Nightingale Telephone (401) 874-5882 Department of Physics, East Hall Fax (401) 874-2380 University of Rhode Island Kingston, RI 02881
