Jeff Hills noted:

> ...I was working my most tranquil hive one recent evening when the bells rang.
> I must say I have never been attacked by so many bees.  As soon as the bells
> stopped ringing (the tune was "A Mighty Fortress is Our God") the bees were
> totally calm once again.

I think the question should be posed as "bees and sound" rather than
"bees and time", but perhaps we could narrow it down further to "bees
as music critics".   :)

How loud are the bells as heard in your apiary?  If the bells were loud
enough, the sound could be resonating on the surfaces of the supers
and hive bodies, making small, but certainly detectable by the bees,
vibrations.

The vibrations are apparently being interpreted by the bees as a
predator (a skunk scratching at the landing board?), and they are
putting up the usual sorties of kamikaze defenders.

In an extreme case, you might be able to place a hand on the side
of a super, and feel the vibrations yourself.  More sensitive equipment
such as an SPL meter (a microphone with a "loudness" meter) or
even accelerometers (solid state devices that detect movement)
might do a better job of quantifying the loudness.

I'd guess that the sound itself is not being directly detected by the
bees inside the hive, for the same reason that a lawnmower is not
as noisy to a person inside a house.

There are a couple of papers on the subject of bees "hearing" by
detecting vibrations.  Here's a few that I hunted down via inter-library loan:

  Kirchner, W. 1993: Acoustical communication in honeybees.
  Apidologie 24, 297-307.

  Sandeman, D. C., Tautz, J. & Lindauer, M. 1996: Transmission
  of vibration across honeycombs and its detection by bee leg
  receptors. Journal of Experimental Biology 199(12), 2585-2594.

  Rohrseitz, K. & Kilpinen, O. 1997: Vibration transmission
  characteristics of the legs of freely standing honeybees.
  Zoology-Analysis of Complex Systems 100(1-2), 80-84.

There is a slight chance that the bees were inspired by the
music to defend THEIR fortress.  The song was "A Mighty Fortress",
after all.  One way to confirm this would be to observe bees
that are "hanging out" on the front of the hive, and watch what
they are doing.  If they are reading the book of the Bible named
"The Beeatitudes", then you may have fundamentalist bees.      :)

        jim