I basically agree with Rob.
I did tests of the sort he describes (more simple-minded to be sure) and d=
etected little/no difference between 48/96 KHz and 16/24 bits. I don't reco=
rd as much as he does so I use 24 bits/ 48 KHz figuring the expense of savi=
ng the extra bits is small as percentage of time and miles driven... UNLESS=
the subject has significant high frequency content. Orthopterans and Chiro=
pterans being the main examples. I actually got the new Sennheiser omnis so=
that I could hear Eptesicus bats. Sonograms work fine but I haven't yet fo=
und a useful transformation and playback system that presents the sounds to=
other people.
I'd be very interested in hearing about other acoustical phenomena at highe=
r frequencies. As was pointed out here, the impedance of air to high Hz sou=
nd is huge --- bats really need to scream to make a living.
Living in Ohio, my main interests are terrestrial. Certainly "nest/family" =
sounds of some other mammals (Shrews eg) qualify.
And I've tried with partial success to hear cavitation in vascular tissues =
of water-stressed plants but can't say I'm happy with or inclined to pursue=
that line.
Does anyone know of other situations where signals above (say) 20 KHz are i=
mportant?
---
I'm off very very early tomorrow for a dawn chorus at a hilltop (http://ohs=
web.ohiohistory.org/places/sw06/index.shtml) with ancient native american e=
arthworks (not that they'll influence the acoustics much...) Is anyone else=
visiting such sites?
Best regards,
Steve P
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