SonoBat Utilities
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A: The AutoParser depends upon a quiescent signal level between bat events, i.e., passes, to recognize and edit out the passes as separate files. The first thing to consider is the audio cord/connection arrangement. The Pettersson outputs the heterodyne signal on the left channel and the time expansion signal on the right channel. The heterodyne signal is continuous (for monitoring passes as clicks), but the TE channel is intermittent in the auto-recording mode. The TE channel is the only data you need for analysis (and for AutoParsing). The SonoBat cords we supply (and directions for making them are in the User’s Guide, also see instructions in this guide) eliminate the HET signal so that the recorded data has a quiescent level between triggered TE signals, and that enables the discrimination of those TE events by the AutoParser. If a standard stereo cable was used, and both HET and TE signals were combined*, then there can be some confounding baseline signal level that makes it difficult to discriminate and parse the TE signals. In such a case you can’t find a sufficiently low threshold setting on the AutoParser to recognize the triggered TE events, and if the discrimination level is set above the noise level it will likely be too high and will only be able to discriminate individual calls rather than entire passes.
If that is the case, you can still manually parse out the TE events. It will be a bigger chore, but the data is there, albeit with extra noise. Prepare the recording as a single wave file, then open in a sound editing software like QuickTIme Pro or Acoustica that lets you view (and listen) the waveform and edit out the snippets to save as individual events.
If AutoParsing calls from a Zoom H2, consider this improved method.
* Despite accepting a stereo cable and having a “stereo” setting, many computer sound cards will just combine the two channels of a stereo signal.
A: You would get that error if the files are not parsing and instead attempting to build one large file without a break to write shorter parsed files. You may not have the threshold set high enough to be above the signal level in between the bat recording events.
Check the instructions on setting the AutoParser’s auto-triggering threshold (push the “?” button to get to that). To successfully parse files, the AutoParser must be able to recognize the signal level when the recorder was not receiving a downloaded recording from the detector, and when it was. The threshold level is how it accomplishes that. When that is working, the AutoParser will find the 17 or 34 second file sections (i.e., time expanded 1.7 sec or 3.4 sec bat passes) and save them to your disk as separate files. These files will be about 1.4 or 3 MB, respectively.
If the threshold is set at too low a setting it will continuously read the file in preparation for writing a parsed file to disk, without a break, filling your RAM to capacity until your memory is full. You need to set the threshold so that the read process breaks in between the recorded events.
Also, if you are using a Zoom recorder, there is no need to copy the entire file from the Zoom. Just read the file directly from the Zoom to parse, and that way you only save the bat content to your disk.
Run the file to parse again with the lower left button set to monitor without saving to set the threshold as per the help instructions:
Adjust the threshold setting so that it remains above the recording level between the call sequences that you desire to record, but low enough that it remains triggered during the entirety of the sequence that you want to capture.
To find the best threshold setting, run the file that you wish to parse with the AutoParser set to monitor without saving (lower left button). Watch the sound input level bar and note the signal level between call sequences and during call sequences.
The AutoParser saves your threshold setting when you close the utility, and will set that level the next time you launch the AutoParser.
If the files fly by too quickly on your recording, you can also calibrate your AutoParser by setting up your detector and recorder up as to record, but have the D240x on manual, and just generate some files by manually clicking the start/stop button in the D240x on and off, giving maybe 10 sec between each click. That should give you a file with good separations between signals to make it easy to set your threshold. You want it as low as you can get it without getting triggered in between signals downloaded from the detector; but if too high, it might write multiple files for a single pass. Once you have set the threshold, upon quitting the AutoParser it will remember that setting and use it the next time you launch the AutoParser.
If AutoParsing calls from a Zoom H2, consider this improved method.
A: You may also be running into the wav file format limitation. Wav files have a limit on the number of samples in the file. For a stereo 44.10 kHz/16 bit wav file (unfortunately there is no mono option on the zoom, which would double this) the max file duration possible is about 13.2 h. Even if you have more memory you still reach this file format limitation for a single file. To record longer you would need to stop a recording and start a new file, or you could record an mp3 file, but then have a massive file conversion to a wav file before you can parse the file.
If AutoParsing calls from a Zoom H2, consider this improved method.
A: Wildlife Acoustics EM3 detectors and SM2 detectors using SMX-UT microphones have subtle frequency response adjustments that optimize their faithful representation of ultrasound recordings. Recordings from SMX-US microphones provide raw, unadjusted data. When SM2 aware, SonoBat will recognize files with sampling rates of 196 and 384 kHz as originating from Wildlife Acoustics SM2 detectors, and will then perform internal routines and adjust settings to optimize processing these files. So, if you are using EM3 detectors or SM2 detectors with the SMX-UT microphone, the SM2 Aware button does not need to be enabled. If you are using SM2 detectors with the SMX-US microphone, the SM2 Aware button needs to be enabled. If you are using a mix of Wildlife Acoustics detectors and microphones, keep track of which recordings are made with with microphones and use the SM2 Batch Attributor with the SMX-UT button enabled to provide compensation for the SMX-US microphone and to add file notes. NOTE: this attributor will replace content of original files, so be sure original files are safely stowed in an archive location and then copy those files to your working directory before running this attributor.