One of our Audiomoth development boards connected to an external alkaline battery pack and a gps unit housed in a waterproof case has a audio recording from using the internal microphone in a lab setting, another using an external microphone in the lab, and one from the field using an external hydrophone while attached to a buoy. On the internal microphone recording there is a constant 8kHz tone present. In the external microphone recordings, both in the lab and field, a regular ticking sound that we suspect is from the GPS transmitting is present.
Has anyone encountered either of these system noises before with this kind of configuration?
Fig. 1 Ticking noise
Fig. 2 8kHz Tone
Hi, Can you share the original WAV files. The regular ticking is often the SD card write interference. What make and model of SD card are you using? Also, can you describe the battery pack in more detail - what size, make and model of battery? Is the sound not present on other AudioMoth Dev boards? Alex