Calls of a bat in our garden recorded with an acoustic logging device in Wrestlingworth Bedfordshire. The device used was the AudioMoth from Open Acoustic Devices an inexpensive audio device often used for wildlife and other acoustic monitoring purposes. Sampling rate was 384 Khz using medium gain on the device. Calls are played back at 22 Khz in Audacity in this video to be audible for human hearing, so slowed down by a factor of about 17.5 times. Analysis of files collected during the monitoring showed that bats were active between about 8:45pm and 6am so about 1 hour after sunset and just before sunrise. Files were processed with a Python script to obtain spectrum and frequency plots and flag files of interest. About 1Gb of data was submitted to the BTO Acoustic Pipeline for online analysis. This indicated a species ID of Common Pipistrelle with over 90% confidence. Research online seems to agree with this I am no bat expert by any means! The peak frequency of the echolocation call seems to be around 48Khz which in consistent with the Common Pipistrelle. This video shows examples of echolocation, social and feeding buzz calls.

Links
AudioMoth: https://www.openacousticdevices.info/...
Audacity: https://www.audacityteam.org/
BTO Acoustic Pipeline: https://www.bto.org/ourscience/proje...
JupyterLab (used to run Python scripting): https://jupyter.org/

UK Bat Conservation: https://www.bats.org.uk/
Bedfordshire Bat Group: http://www.bedsbatgroup.org.uk/wordpr...
Common Pipistrelle Info (University of Bristol): http://www.bio.bris.ac.uk/research/ba...