http://www.sfu.ca/sca/Manuals/ZAAPf/r/range.html
The human hearing range is from 20 Hz to about 20,000 Hz.

The below was more concerned with distinguishing "loudness"  (phons) between
500 and 1500 hz -- see
http://www.sfu.ca/sca/Manuals/ZAAPf/e/equal_loud_cont.html.  Fewer decibels
are required for humans to hear in the 500-1500 Hz range (10db), while more
decibels are required at higher and lower frequencies to be perceived as the
same loudness.  Actually, we hear best at about 2,000 Hz. Thus, a 10 db
sound in the 1500 range will be "heard" as much louder than a 10db sound at
250 Hz (and possibly not hear at all by someone with a level of deafness).
According to the graph, the same 10db sound that would have been perceived
at 500-1500 Hz, is "inaudible" (below human perception) at 250 db (the graph
shows about 20 db needed to hear at that frequency).  We can here at 250 Hz
quite easily (men better than women, in fact).  The point of the
inaudibility" is the difference between hearing a radio tuned next to you,
versus one at the same loudness six blocks down the road (different db at
that point).

The same web site (and many others, as well) has some pretty good
explanations and graphs on the entire audio subject.

-----Original Message-----
From: Bob Harrison

(The loudness level in phons is a subjective sensation--- this is the level
we perceive the sound to be at) From about 500hz to roughly 1,500 hz the
line is flat on the 10b scale.

Does the above not indicate that human hearing of sound begins around 500
hz?

Would not 500hz be in line if the Michelson quote was correct saying that
between 250hz to 300 hz was inaudible to humans?

Even with my limited knowledge (and your saying that the quote I presented
by Michelson 1987 should stand) I can not help but to believe that 250 to
300 hz is beyond the hearing range of most people working a bee hive
outdoors.