Hi Rupert:

If you look at the plot at:
http://people.xiph.org/~xiphmont/demo/neil-young.html
showing threshold of hearing and threshold of pain, at the upper frequency =
end the two curves intersect, but at the low=20
frequency end the plot has been artificially truncated.  It's clear the peo=
ple can hear sounds lower the 20 Hz, it's=20
just not plotted. Yes it takes more power to hear, but when that amount of =
power is present you do hear (and not=20
experience any pain).
http://www.prc68.com/I/HomeTheater.shtml#SSS

When I watch movies on a 7.1 surround sound system (the ".1" is the sub woo=
fer) you really do experience those low=20
frequencies.

Note elephants and other animals can generate and hear infrasound that we c=
an not hear.
http://www.prc68.com/I/Sensors.shtml#Isnd

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

piclist-request@mit.edu wrote:
>   [OT] Audio frequencies

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