I wrote an Android app to visualize spectrograms.
It's been a little frustrating. Unfortunately, at least with my Google Pixel 7 Pro. While the system happily records at 192khz both with its internal microphone(s) and with the external AudioMoth, in both cases the input is filtered to below 25khz. Which is an understandable measure for a "phone" that is supposed to work best for Human speech. Unfortunately, it does not support the "UNPROCESSED" audio source as some other Android devices seem to do.
I also verified that the AudioMoth is used by the Android app, rather than the internal MIC, and that the AudioMoth picks up frequencies above 20khz correctly when connected to a PC.
At this point there doesn't seem to be a workaround, even though the filtering must be in software, when it is applied to the USB microphone.
There is another post that mentions that the AUDIO.
Does anybody else have suggestions or informations on this?
I think it actually works now. Turns out, it's harder to produce ultrasound for testing than I thought. I'm not a bat, after all!
Hi Andreas, This may vary for device to device. We've previously used Android devices with AudioMoth USB Microphone to record bats, and in the past in an app intended for recording cicada we've had experience of some Android phones filtering audio and others not. This didn't seem to be associated with the cost of the device. Alex
I too had a look at writing a new recorder app for Android (to supply the deficiency while Bill Kraus BatRecorder is fatally broken), hopefully in .NET so that it could be made cross platform with a bit of extr effort writing device specific front ends. Unfortunately I go bogged down in the USB Audio interface which seemed to be reluctant to admit to the existence of a microphone other than the built-in microphone without going deeply into the USB interface itself - which seemed to be very poorly and confusingly documented. Certainly very little if any references to handling sample rates above 96kHz. I for one would be pleased to hear of anyone who gets this to work and who is prepared to open up their work as Open Source. Soory not to be more helpful!