Contact David King at Stag electronics http://www.batbox.com/ and

explain what you are doing. I assume he now works full time making and
selling bat detectors, but before this he was Director of Music at St Donut=
s
College here in South Wales, and indeed composes music using bat ultrasound
calls. So he may be interested in helping with the project. He is also base=
d
in Steyning, so not that far from you.