[pianotech] Discovery surprise

[Albert Picknell]

--- On Mon, 3/14/11, Ron Nossaman <rnossaman at cox.net> wrote:

> Sitting at my desk during breakfast, with a dead internet
> connection, I got to playing with a cheapo sound level meter
> (Realistic, Radio Shack), and discovered something I thought
> interesting. On the 80db scale setting, a normal
> conversational voice level is in the zero+- range, right
> about there from maybe 10cm from the mic. Interestingly, so
> is a high frequency florescent bulb, about the same level
> from the same distance. These are the florescents that screw
> into the same fixture as an incandescent bulb. I can't get a
> frequency reading on the bulbs, but they're sure a lot
> louder than I expected. We're apparently steeped in a sea of
> noise that we're not entirely aware of, wherever we go that
> these bulbs are used. Regular incandescents, and long tube
> florescents (shop lights) don't do that.
> 
> Fun stuff from the cheap seats.
> Ron N


Hi Ron

I'm not surprised, actually.  I often have to leave rooms that have these lights because of the noise they emit.  I divide these high-frequency fluorescent bulbs into three kinds: 1. those that emit a sound that is clearly audible, and I have to leave the room; 2. those I can't clearly hear, but I can still feel the vibrations penetrating my brain (I also have to leave the room); 3. those I can't hear or feel at all.  Perhaps with the second type the sound being emitted is just at the edge of my hearing range, and with the third type the sound is well beyond my hearing range.  Just guessing.  I suspect that with long-term exposure, all of them do damage of some kind.

I wonder what dogs hear when they're around these things.

Bert