Students listened to the calls from Romania and the Transylvania region. Per the website: "Transylvania is a part of Romania, where the Romanian Bat Protection Association have been responsible for involving more than 100 volunteers in the collection of thousands of hours of acoustic recordings from microphones attached to cars driving over 50,000 km around some very bumpy roads! These data make up a large part of the calls in Bat Detective."
Do you want to try it? Visit http://www.batdetective.org to begin your own spooky journey.