Bat Recorder

88 reviews
Content rating
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About this app

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
Updated on
Apr 13, 2020

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
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Ratings and reviews

79 reviews
A Google user
September 25, 2019
This is a fabulous app. I've tested it with the new Pettersson u256 microphone on Moto G4 and G7 phones and it works brilliantly. My dissertation students are now using this for their summer bat projects. The ability to export GPS data for each file or folder is awesome. One minor gripe is that there is so much fantastic functionality in here that isn't detailed in the manual, so there is a bit of trial and error to get things just how you want them. Once you have it set up though it is superb.
28 people found this review helpful
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May 22, 2020
Wonderful application. Lots of options (tip: carefully read the manual located in the options menu). I get excellent sound with the Petterson M500 384 combined with this app on my Samsung S8. On a full battery I can use the app for 2.5-3 hours. It really has everything you need from a bat detector. Especially the sonograms and 10x time expansion are very useful. I use it to record all activity (in 5 minute blocks) which means full spectrum recordings of the entire time in the field.
22 people found this review helpful