> If something like a Songfinder is an acceptable solution, there are far c=
heaper bat detectors available. I bought a "Discovery Kids Ultrasonic Detec=
tor" on eBay for about $40. It's a heterodyne detector, and is of course a =
toy compared to some, but it seems to work ok. I suspect though, that a sof=
tware solution would be better.
This kind of heterodyne functionality is available in the free Avisoft-SAS=
Lab Lite software (http://www.avisoft.com/downloads.htm or http://www.aviso=
ft.com/SASLab%20Lite.exe http://www.avisoft.com/SASLab%20Lite.exe). Just op=
en the .wav file and activate the option "enable heterodyned playback" from=
the menu "File"/"Heterodyned Playback mode...", where the center frequency=
and bandwidth can be adjusted. If you then play the file by clicking at th=
e play button, you will hear the heterodyned signal just like on an analog =
heterodyne bat detector.
The same software also allows to down-shift portions of a waveform using F=
FT (command "Edit"/"Filter"/"Frequency Domain Transformation..." > "Frequen=
cy Shift").
The SASLab Pro version (which is unfortunately not free) would also allow =
re-synthesizing any whistle-like sounds using its Graphic Synthesizer tool,=
which allows modifying time and frequency scales independently.
Regards,
Raimund
Avisoft Bioacoustics http://www.avisoft.com
http://www.avisoft.com
Avisoft Bioacoustics http://www.avisoft.com Avisoft-SASLab Pro - Bioacoust=
ics Laboratory Software is a versatile sound analysis, editing, classificat=
ion and synthesis tool.
View on www.avisoft.com http://www.avisoft.com
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