Peter,
I've tried recoding bats on Olympus LS10 at 96 kHz, with electret
mics, not very successful, possibly because the electrets just can't
cope with the high frequencies. But if you've got that gear already,
then give it a try. Certainly works for the White-striped Freetail
bats (their calls are around 13 kHz and audible to humans).
Vicki
On 01/03/2016, at 1:52 PM, Peter Shute
[naturerecordists] wrote:
> Thank you very much for that information, Raimund.
>
> Can anyone tell me how well a PCM-M10 would record bats with either
> the built in mics or external EM-172 mics? I can set the recorder to
> the highest setting, 96kHz, which should be able to record half that
> frequency?
>
> Also, is there a recorder in the same price range that can record at
> 192kHz?
>
> Peter Shute
>
> From:
>
> Sent: Sunday, 21 February 2016 9:02 PM
> To:
> Subject: Re: [Nature Recordists] Hearing Bats that been recorded.
>
>
>
>> Nice. Is there a limit on the length of the wav file? And can you
>> save the heterodyned sounds? David could just mix it into his
>> recording.
>
>
>
> Hi Peter,
>
>
>
> The SASLab software can open common .wav files of up to 2 GB in size
> and the heterodyned playback has no limit on the length of the file.
> In order to accelerate opening large files I would recommend to
> activate the option "File"/"File Open Settings..." > "do not create
> a temporary copy (limited undo!)"
>
>
>
> The Frequency Shift function on the Frequency Domain Transformation
> dialog box has however a limitation on the duration (it is intended
> only for processing a few calls at once) and it will only work on
> mono files (the software has been designed primarily for bioacoustic
> research, which seldom requires stereo).
>
>
>
> There is no direct way to save the heterodyned sounds. But it could
> be done as follows:
>
>
>
> 1. Launch the Dialog box "Edit"/"Change Volume..." and select the
> Option "Modulation freq." on the section "Amplitude Modulation /
> Multiply by".
>
> 2. Enter here the desired tuning (center) frequency, such as 40000
> Hz for instance and click at Ok.
>
> 3. Low-pass filter the resulting amplitude-modulated waveform from
> "Edit"/"Filter"/"Time-Domain IIR Filter..." (use here the option
> "Low Pass" and enter a cutoff frequency (fco) of about 10 to 20 kHz.
>
> 4. Save the modified file from "File"/"Save As..."
>
>
>
> Bye the way, the software can also be easily configured for time-
> expanded playback. Just go to "File"/"Playback settings...", check
> the option "other sample rate" and select here a sample rate of for
> instance 11025 Hz. Don't forget to disable the heterodyned playback
> mode in case you tried it before.
>
>
>
> Regards,
>
> Raimund
>
>
>
>
>
>
>
>
>
>
> ------------------------------------
> Posted by: Peter Shute <>
> ------------------------------------
>
> "While a picture is worth a thousand words, a
> sound is worth a thousand pictures." R. Murray Schafer via Bernie
> Krause.
>
>
> ------------------------------------
>
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