It’s usually pretty easy to spot sounds above 500Hz in spectrogram analysis software, but many important bioacoustics happen way below that frequency and can often be overlooked. In this tip from the team, we’ll show you how to visualise low frequency sounds in AudioMoth Play, our online tool that lets you view, listen to, and analyse your AudioMoth recordings. You can use this tool to view WAV files, experiment with filters, tweak the configurations and export them for use in the AudioMoth Configuration App and then apply them to the AudioMoth hardware. 

Here is a video made from AudioMoth Play of an elephant rumble. It has been played back twice as fast so you can hear the infrasonic rumble. It is displayed at the 8kHz sample rate it was recorded at. You can just about make out the elephant rumble at the bottom of the spectrogram. 

To see the low-frequency bits…