[Chris Hornbeck]

On Tue, 1 Jul 2008 21:19:52 -0700, "Jerry Steiger"
wrote:

The microphone is used to record field notes or possibly for voice commands.
The speaker is used mainly for notifications and the normal computer beeps
and squeaks. I suppose people could play music over it to (thats how we used
to test them), but there are much smaller systems that would sound much
better and most everybody already has one, just like cell phones.

Sometimes the unit is mounted on a tripod with surveyor's instrument. In
that case it is roughly three feet off the ground and three feet away from
the surveyor's head.Sometimes it is mounted a pole, putting it a little
farther from the ground and closer to the surveryor, say 4 feet up and 2
feet away. Sometimes it is just held in a persons hand, so it could be as
close as a foot and a half or so.

Sounds like a cool project. So you really need to measure
voice intelligibility, and likely with a pretty serious
and unpredictable noise background?

I say this because I see surveyors all the time working
right beside (or occasionally, in) the roadway. Traffic
goes by with noise levels of what? 75dB SPL (C)? 90db?
Could be even more with the dump truck or Harley option.

Another way of saying this is that I really wonder if the
model of measuring the hi-fi quiet-background aspects of
the box is going to matter to you at all. Maybe so, but
my guess is only very, very indirectly.

Voice intelligibility is often a surprisingly non-hi-fi
product, with severe bandwidth restrictions, dynamic
range compressions, sometimes even deliberately added
distortion (!) parts of the final mix.

Wiser folks have already suggested that this is a very
specific question for a very unusual use, so I'm only
riffing on their ideas when I propose that you consider
connection to a Bluetooth headset. Folks walk around
with these things all the time already, pretending that
they've been assimilated. Just a thought.


All the best fortune,
Chris Hornbeck