About & Pics
This app works in conjunction with a separately purchased USB ultrasonic microphone to record and analyze ultrasonic bat echolocation calls (and thus can be used as a bat detector), as well as other high frequency bioacoustic signals from cetaceans, insects, and other animals. It can also be used to record audible signals such as bird songs using a non-ultrasonic USB microphone.
The app supports many USB microphones (ultrasonic or not) that conform to the USB audio class specification, such as any Dodotronic Ultramic USB microphone or Hydromic USB preamplifier, the Pettersson Elektronik M500-384 ultrasonic microphone (note that the M500-384 is a different model than the Pettersson Elektronik M500), Avisoft's UltraSoundGate 116Unb ultrasonic microphone, or the non ultrasonic Samson GoMic USB microphone. The app also supports Binary Acoustic Technology's miniMIC line of ultrasonic microphones. By default, the app will use the highest sampling rate supported by the USB microphone - however, the app's Settings allows for specifying other sampling rates if the USB microphone supports this feature. Note also that the app records in 16-bit mono only.
The app can also be used to record audio from the Android device microphone or from frequency division, time expansion, or heterodyne bat detectors using an audio cable plugged into the TRRS jack. However, please note that in these cases, the incoming signal is not ultrasonic.
This app displays a real-time spectrogram (on a linear or logarithmic frequency scale) and the wave amplitude for both incoming signals, as well as for previously made recordings (saved as uncompressed, geotagged WAV files). The display can be zoomed, and the visualization can be enhanced using a variety of configurable color palettes. The app also can display a power spectrum for any point in a recording. Finally, in order to facilitate quick field measurements, the app has a 'caliper' tool, which attempts to place a frequency and time axis overlay on top of any sound feature that a user double taps on.
This app supports the ability to audibly monitor ultrasonic sounds simultaneously while recording, using real-time frequency division, heterodyne tuning (manual and automatic), or frequency low pass filtering of the incoming signal. Recorded ultrasonic signals can additionally be played back in the audible range using time expansion. Time expanded versions of recordings can also be exported.
This app also can be set up for recordings to be triggered automatically based on frequency and intensity. In addition, listening periods can be set up using a timer, and the app can send SMS messages and/or emails whenever a recording is automatically triggered.
The app can store metadata (location, recording device model, time stamp) inside recorded WAV files using either the XMP or GUANO metadata format. The app can also save recordings directly to a writable SD card if your Android device supports it, as well as export GPS Exchange File formatted tracks, useful for transects.
Please note that the USB microphones require an Android device that supports USB OTG for power. In addition, you must use a USB OTG cable (a standard USB cable will not allow a USB microphone to be powered). This is not a requirement for non-ultrasonic microphones plugged into the TRRS jack.
IMPORTANT note to Android 6.0+ users: The location permission and SMS permission are optional - the location permission is only needed to geotag recordings, and the SMS permission is only used to send text messages when a triggered event occurs. All other permissions must be granted for the app to run - otherwise you will get a permissions error message.
A PDF version of the Bat Recorder user manual in several different languages can be found at http://manuals.batrecorder.com.
Releasing new versions every 14 days, on average.
Fixed continuous recording bug.
The app now displays a simple indicator that shows the number of the current displayed playback file relative to the total number of files in the current directory (eg 3 / 8).
Bat Recorder now recognizes the Echo Meter Touch device.
Bug fix to prevent the app from freezing when using the caliper tool.
Fixed an issue where the app would crash if the user attempted to open a wav file that was not in the uncompressed format. Now these files will no longer be visible from the app.
Updated translation of the Dutch version.
Added Myotis dasycneme to European region species list. Changed disconnected microphone warning to explicitly refer to a USB OTG cable. Fixed a layout issue for the splash screen on very high resolution devices.
Minor code fix.
Minor bug fix in case when loading third party wav files where XMP metadata indicates geodata but coordinates are missing.
Minor bug fix to USB library.
Added support for storing environmental data (if your Android device has the appropriate sensors) to the WAMD (Wildlife Acoustics Meta Data) format. Bat Recorder already supported storing such environmental data in GUANO and XMP metadata formats..
Attempted file name cache fix when transferring files to Windows thru USB.
Italian language correction.
Responding to a user request, added the ability to view either channel of a stereo recording (created outside of Bat Recorder). Note that saving clips of a stereo recording will be saved as a single channel recording only.
Renderscript support fix for Android 4.2.
Optimization of multiple thread concurrency, resulting in a performance improvement when receiving data from the microphone.
IMPORTANT UPDATE. Please upgrade to this version as it has an important fix for a data sizing bug that was introduced in a recent update as part of some code optimizations. This version also fixes a minor bug where the number of files in a directory that the app displayed in the archive dialog was off because it erroneously included non-recordings in the count.
Fixed a bug where the app was assuming recordings should be saved to the SD card (if one is available) by default. This has been corrected so the app defaults to saving to internal storage. (You can open the archive window and look at the SD card icon - if your device supports external SD cards - in the upper left corner to confirm whether this preference is set or not). Also, based on a user request, added a setting to force the Android system bars to always be visible.
Some minor platform configuration changes.
Fixed a bug that assumed a location was always available even if it was not.
A few more optimizations and code cleanup.
Fixed a bug that could cause a crash if opening a file with GUANO metadata missing a timestamp.
Based on a user request, added options for shorter intervals between GPS location updates. Please remember that more frequent updates will use more battery power.
Fixed a bug that left the system task and navigation bars visible after a dialog was displayed.
Fixed a bug where the system navigation bar wasn't hiding after returning from viewing the file archive list..
Exported clips will now save to the same directory as the original file. Bug fix for occasional hangs during playback of previous recordings. Added a 'CSV' button on the archive panel that will save a comma separated text file to the top level directory of the Android device, and containing summary data (GPS coordinates, recording device, length, file name, etc) for all the recordings within a directory.
The app now asks for permissions when running under Android 6.0.
Fixed a bug introduced in the last version where the maximum recording length was not being respected if the listening buffer was captured. Responding to a user request, added a setting to enable all playback modes even when the recording is non-ultrasonic. Added more information logged during USB device debugging.
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