Screenshot of SM2 batch convertor panel. This utility will batch process files or directories of files from Wildlife Acoustics SM2BAT detectors to enhance the signal levels of the files to enable optimal processing with SonoBat and render the files to have similar appearance and response as those from other detectors, e.g., Pettersson or Binary Acoustic Technology.

This Wildlife Acoustics SM2BAT detectors produce files with subtle differences in frequency response and signal level than files from other bat detectors such as those from Pettersson or Binary Acoustic Technology. This affects their analysis using SonoBat, particularly when comparing with SonoBat reference files and when using the SonoBat automated classifier as both of these use files acquired using Pettersson or Binary Acoustic Technology detectors. In many cases the signal differences between recordings made with different detectors can exceed the already subtle differences between the calls of some species. Post-processing compensation can adjust the raw files from SM2 detectors to yield comparable results to others when analyzed using SonoBat.

Post-processing of SM2 files involves two steps:

1) SMX-US compensation using the Wildlife Acoustics wac2wav converter to compensate for differences in the frequency response of the MEMS microphones that SM2 detectors use.

Download the most current version of the wac2wav converter (Mac or PC) from the Wildlife Acoustics download page:
http://www.wildlifeacoustics.com/downloads.php
Current version 3.2.3 as of this writing.

Note: Recommended recording settings: WAC0 and 48 dB gain.

When processing WAC files with the wac2wav convertor select a 3 or 5 second split trigger to best separate bat passes and select the SMX-US filter. Check the SonoBat box and enter any descriptive or field notes to attach to each file that will display in the note field when opening the files in SonoBat.

2) Next, batch process the wav files generated by the wac2wav converter with the SonoBat SM2 batch compensation utility. This will batch process files or directories of files to enhance the signal levels of SM2 files to enable optimal processing with SonoBat and render the files to have similar appearance and response as those from other detectors, e.g., Pettersson or Binary Acoustic Technology.

Note: Files must first have SMX-US compensation when processed to wav files using the Wildlife Acoustics wac2wav converter to achieve full compensation.

Use the default a, b, and c parameters unless otherwise instructed. These settings may be changed if new results indicate more optimum settings, or if different adjustments become necessary, e.g., from subsequent versions of the wac2wav converter or if using different equipment. The original default settings of 3200, 12, and 1.1 for a, b, and c, respectively were optimized to work for Myotis species calls using files from an SM2-384 kHz converted using the wac2wav converter version 3.2.3.

If changed, the SonoBat SM2 batch compensation utility will update a settings file that will set these parameters to the updated settings upon subsequent launches of this utility. Right-clicking and selecting  "Reinitialize to Default Value" will return a parameter to the default value of the original release.

User notes

The combination of microphone differences and the conversion and compensation processing may yield more noise in the resulting SM2 files. You may want to adjust your SonoBat preference setting (lower left of Son Bat panel) for acceptable call quality downward from the default setting of 0.80 to 0.75 or 0.70 to compensate and enable the consideration of more calls. Use caution to avoid too many low quality calls to pass through as acceptable as that may compromise correct classification with SonoBat 3.

The importance of acquiring quality recordings and how to do comprises one of the primary things we teach in bat acoustic training workshops. Ultrasound behaves differently than the sounds we know and interpret. For best performance and results, as much as possible avoid noise and endeavor to acquire noise and distortion-free recordings. See the slides regarding noise in this SonoBat 3 presentation and refer to the the SonoBat recording advice page for more tips.

1) Download and unzip this file:
http://www.sonobat.com/download/SM2_batch_compensator_Win.zip

2) Move the SM2 batch compensator.exe and SM2 batch compensator.ini files into your SonoBat Suite folder.

3) Right click on SM2 batch compensator.exe and copy.

4) Go to your start menu, All Programs and navigate to your SonoBat Suite folder and right click on the folder and select Open. Right click and select Paste Shortcut.

The SM2 batch compensator will now run from your Programs menu.

1) Download and unzip this file:
http://www.sonobat.com/download/SM2_batch_compensator_Mac.zip

2) Move the SM2 batch compensator.app and SM2 batch compensator.ini files into the SonoBat folder in your Applications folder.

3) Move a copy of the SM2 batch compensator to you dock, if desired.

The SM2 batch compensator will now run.