Frequently Asked Questions

Q:Why didn't SonoBat classify all the bats in a two hour recording?
A: The design of SonoBat processing and its utilities optimize it to handle files with durations typical of individual pass events. And it considers each file you feed it as one event, and will only output a single decision for any file it processes. It is not designed to sort out the individual passes in a continuous recording- it leaves that up to the recording hardware. Most detector hardware will trigger and output individual files of bat pass duration length, .e.g., of 3, 5, or 8 seconds of duration or up to about 5–8 MB. If you throw bigger files than that at SonoBat it will likely choke with a memory error because of the processor-intensive work it does to interpret the signals at a high level of scrutiny. If you record in a way that produces files greater than 10 seconds or so, you will not resolve individual bat passes (i.e., such long files would likely have more than one bat pass). In addition to subverting activity counts of passes, that will also subvert the classification process that considers the strongest signal in any one file.

Q: SonoBat crashed and recorded a memory error when I attempted to scrub a batch of files?
A: SonoBat and its utilities can only handle files with durations typical of individual pass events. Most detector hardware will output bat pass duration files, .i.e., of 3, 5, or 8 seconds of duration or about 5–8 MB. If you throw bigger files than that at SonoBat it will likely choke with a memory error because of the processor-intensive work it does to interpret the signals at a high level of scrutiny. If you record in a way that produces files greater than 10 seconds or so, you will not resolve individual bat passes (i.e., such long files would likely have more than one bat pass). In addition to subverting activity counts of passes, that will also subvert the classification process that considers the strongest signal in any one file.

Before running any batch process, check the directory display of the files you put in that batch job, and sort them by file size to see if you have any large files. Some recording setups will sometimes deliver huge files.

Best to avoid generating large files not just because they choke SonoBat but also because they can have multiple bat passes in them and subvert the automated species classification and tallying individual bat pass events
.

Best to avoid generating large files not just because they choke SonoBat but also because they can have multiple bat passes in them and subvert the automated species classification and tallying of individual bat pass events.

Q: Will SonoBat work with my Anabat detector?
A: No, because the Anabat uses zero-crossing, a different operating principle than full spectrum detectors. Zero-crossing does not acquire sufficient signal information to render full spectrum, high-resolution sonograms.

Q: I can't get the AutoParser to discriminate calls in my recordings?
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 autorecording 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 impoved 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.

Q: I get an error message when I attempt to AutoParser call sequences from files I record with a Samson Zoom?
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 autotriggering 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 impoved method.

Q: I get an error when I try to parse more than about 13 hours of a recording from my Zoom H2.
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 impoved method.

Q: How can you power Pettersson D240x detectors for longer periods than can be supported by a single 9V battery?
A: The D240x can accept 12V. We use 12V battery systems for our field recorders. You can use any gel cell or 12 V battery up to your need. We get them from here
http://batterystuff.com/batteries/
You just need to attach a matching 9V connector (with the polarity appropriate: positive-male; negative-female) to connect to the D240x. Also, put an inline fuse (1A) on the positive line from the battery to protect the D240x. You can also integrate recording devices and a solar panel into such an arrangement. A D240x draws about 30 mA of current.

Q: How can I protect my detector from rain if I leave it out overnight, or for days at a time?
A: See page of recording advice.

Q: What are the hardware requirements for running SonoBat?
A: Windows: Pentium with at least 512 MB of RAM (1 GB or more recommended), about 120 MB of free disk space (more will be needed as you collect calls). To directly transfer audio signals from a bat detector to your computer, the computer must have a sound-in port, e.g., a microphone port.

Macintosh: PowerPC with OS X and at least 512 MB of RAM (1 GB or more recommended), about 120 MB of free disk space (more will be needed as you collect calls). To directly transfer audio signals from a bat detector to your computer, the computer must have a sound-in port, e.g., a microphone port.
Note: Macintosh iBooks do not have a sound in port, but you can adapt one to have a sound-in port with a Griffin iMic via the USB port.

In addition to the computer, a bat detector capable of processing time expansion sequences. As a basic unit, we recommend the Pettersson D 240. Three of the Pettersson units that work well with SonoBat have an autotriggering function that will automatically retain and deliver time expanded call sequences to a tape recorder. Recorded calls can then be downloaded into the SonoBat program for processing and analysis. Those models are the D 240x, the D500x and the D 980, with the D 240x as the more economical of the group. You can read more specifics about these units at the Pettersson web site. Binary Acoustic Technology, Wildlife Acoustics, and others make full-spectrum detectors compatible with SonoBat.

Q: I've followed the instructions in the User's Guide for setting the gain on my computer's sound card, but I still can't get the signal low enough to avoid overloading the signal level.
A: (Windows) First, make sure that you have enabled the advanced settings for your microphone volume settings, and checked these advanced settings to disable any microphone boost settings, e.g., +20 dB gain.
If that doesn't remedy the overload, you may have a laptop with an exceptionally sensitive sound card, and you will need to use an attenuation cable between your detector and computer. You can get one from

Trew Audio, Inc.
220 Great Circle Road
Suite 116
Nashville, TN 37228-1798
voice: 615-256-3542 or 800-241-8994
www.trewaudio.com

They will make a custom cable for you. Request a 20 bB attenuation. Just ask for the same type of cable that Joel Tigner ordered.

Q: Aren't time expansion bat detectors more expensive than zero-cross units?
A: Not necessarily. There is a greater variety of time expansion detectors available than zero-crossing detectors, some of which have special features and high prices. But a basic unit such as a Pettersson D 240 will yield excellent results and has a comparable cost to an Anabat detector together with the requisite ZCAIM unit needed to interface with a computer. No extra interface unit is needed to use a time expansion detector with SonoBat (see below). Most of the recordings displayed on these web pages and in the SonoBat demo were made using a similar Pettersson D 140.

Q: Does SonoBat require a special interface module to download call sequences into the computer?
A: No, SonoBat uses the built-in sound-in port on your computer. If your computer has a port with a picture of a microphone over it, then you are ready to go. A custom audio cable is included in the SonoBat package.

Q: But my iBook and my new titanium G4 PowerBook don't have audio ports?
A: Yes, silly thing from the company that pioneered multimedia. But the solution is simple: the Griffin iMic creates an audio port using the USB connection.

Q: How can I use SonoBat in public presentations about bats?
A: SonoBat can add a great enhancement to bat talks. Go to our resources page, and follow the link there for suggestions.