Just a temporary update post, (an FYI) for owners of The new Baton XD from BatBox. This reminds me of a "Technical Bulletin" commonly issued to Service Departments of computer hardware systems...
A recent post, from BatBox Ltd. --
"Anyone using the Baton XD bat detector may be interested to know that
last night whilst using it I discovered an additional unplanned feature.
I'd left the connecting lead in the car
but remembered the smartphone. When I opened one of the Spectrogram
apps, Spectral Pro, it picked up the expanded bat calls from the XD
speaker through the phone mic. and displayed them quite clearly on the
Android screen. Although phone screens are relatively small, it is
quite possible to distinguish the call traces of all three pip species,
plus noctule, serotine and myotis (not to species level) without the
connecting lead. Of course this requires a fairly quiet background. I
know the mics on phones, these days, are easily capable of covering a
range of 12kHz so, theoretically, should be able to handle time expanded
calls of all British bats."
There you have it, something new to experiment with!
Happy bat detecting!