OpenBat

OpenBat is a free iOS app that turns a compatible ultrasonic USB microphone into a live bat detector. It captures audio at up to 384 kHz, shows a real-time spectrogram, detects individual echolocation pulses, and, where an open-source model exists for your region, suggests species IDs on-device. Currently covers the US and Canada, with UK/Europe in beta. ** Bat detection requires an external ultrasonic microphone. Visit OpenBat.app to learn more. ** Hear bats in real time OpenBat uses two ways to turn ultrasonic bat calls into sound you can actually hear: - Heterodyne: tunes into a band of frequencies and scales it down. Preserves rhythm and loudness, but can sound clicky. - Time expansion: records a call, then plays it back at a fraction of the speed. Preserves the character of the call, but not the rhythm. - Het + TE hybrid: both running at once. Analyse your recordings Record what you hear, then break down the calls in Playback. Extract the parameters used to identify species, save them for later, or post recordings straight to iNaturalist for the community to help confirm an ID. Learn about bats AutoID suggests which species might be around you in real time. The Field Guide covers bats in your area and worldwide, curated by bat experts and kept up to date — and if you know your local bats, you can contribute too. Share it, or keep it to yourself Play the bats you're hearing through your device's speakers, or plug in headphones and listen alone.