Greg. Yes I have used such devices and the problem is that you hear
everything else as well. Unfortunately you can't filter out the rustling of
leaves in the wind or the crunch of your feet on the ground. They were very
good for standing at the edge of the lake on a still night and hearing the
conversation of fishermen in their boat some distance away but even then the
background traffic noise was a problem.
I'm sure that there will be highly sensitive directional mics that would
reduce the background problem considerably but these would not meet your
'reasonable price' criterion.
Colin Driscoll
-----Original Message-----
From:
On Behalf Of Gregory Little
Sent: Sunday, 10 December 2006 3:54 PM
To: 'michael norris'; 'Tim Murphy'; 'Birding-aus'
Cc:
Subject: Songfinder question
Gooday birders
On the subject of enhancing sound for the hard of hearing. I made inquiries
years ago re a sound enhancing device that would allow me to hear barely
audible sounds at night. I was going to use it to listen for and to owls and
possums etc especially those that may be calling far off and that I may not
have otherwise heard. It would be interesting to listen to sounds between
possums etc and rustling in the leaves that we may otherwise not hear with
normal hearing. I have often wondered whether dogs hear insect bats zipping
about the place. We can hear a few but the call frequency of most bats is
above human hearing. Anyway, for explanations sake we use binoculars to see
details in distant objects or to see close objects better. Why do we not
have some sort of hearing device, for folk with otherwise good hearing, that
allows us to hear faint sounds of a night or in quiet locations, so that
rather than cupping our hands to our ears and straining to listen we can put
the ear plugs in and point the device in whatever direction and hear clearly
sounds that we would not hear. I was told that if we did use such a device
and a sudden loud noise occurred we could be deafened. But the same goes
with binoculars when accidentally pointed at the sun or when reflections on
water are viewed. I hope you understand what I am talking about. Has anyone
heard of such a device and are they already available at a reasonable price.
I am sure the police and military already use something like this.
Greg
-----Original Message-----
From:
On Behalf Of michael norris
Sent: Sunday, 10 December 2006 2:34 PM
To: Tim Murphy; Birding-aus
Cc:
Subject: Songfinder question
Bat detectors shift frequencies into the audible range with the cheapest
being about 100 Aussie dollars.
You can find the circuitry on the web.
There's an opportunity here for an entrepreneur to modify them to shift bird
song to lower frequencies.
Michael Norris
|
