Three additional comments, Bob.
I work in a EM - secure building. No EM gets in or out. We can't even pick up
radio signals from a strong radio station a quarter mile away in here, so any tones
I hear at work are probably due to mechanical rather than electromagnetic sources.
Second, on checking the GOES X-ray flux, I find there was a sudden increase
in X-ray flux recorded at GOES which occurred simultaneously with the ear tone.
The minute-by-minute data can be found at:
http://sec.noaa.gov/ftpdir/lists/xray/20011127_G10xr_1m.txt
http://sec.noaa.gov/ftpdir/lists/xray/20011127_G8xr_1m.txt

The flux increased by about 5 times at 7:54 - 7:55 over that of 7:53 UT. The ear
tone was recorded between 7:54 and 7:55 UT (accurate through Standards Time clock).

Third, there was a moderate earthquake recorded in Nepal at 07:31 UT last night.
The S-wave from this event would have just barely grazed where I am - at about 109
degrees from this event very near the S-wave shadow zone boundary - but just
outside of it. The S-wave would have arrived here about 26 minutes after the earthquake
or at 7:57 while a PPP wave would have arrived at 7:54. However, given the strength
of the ear tone and the relatively moderate magnitude of the Nepal event, it seems
unlikely this was the cause.

In the past, I have noted on this board the correlation between my ear tones and strong
changes in X-ray flux occurring simultaneously with them. While different people may
be more sensitive to different environmental influences in terms of eartones, it appears
that in my case, at least one of the causes of these tones is a sudden increase in
solar X-ray flux in the earth environment. This in turn causes sudden changes in the
geomagnetic field. although in this case no changes were recorded in the geomagnetic
field strength at the time of this ear tone.

I'm not sure how the X-ray flux change translates to an ear tone, though, especially
in a EM-secure environment.

I have also observed on this board that X-ray flux changes often appear simultaneous
with strong earthquakes, perhaps as a triggering mechanism. If some of the other
ear tones people are reporting are also related to changes in X-ray flux changes, this
could begin to explain some of the correlations between ear tones and subsequent
earthquakes.

• GOES X-Ray Flux