Bat Detector vs OpenBat

Simply connect an inexpensive ultrasonic USB microphone to your iPhone or iPad and open your ears up to the extraordinary world of bat acoustics.  Build a dedicated USB microphone for under £10 : https://shorturl.at/e2A3U - : or buy one pre-assembled and tested for about £65 that also operates as a standalone bat detector https://www.apodemus.eu/nl/Apodemus-Pipistrelle-Mini/00126 All European bats and most of the world's "microbats" navigate, hunt and communicate using ultrasonic sounds, too high-pitched for human hearing. Bat Detector reveals those sounds to human ears, and has two different methods to make ultrasonic bat sounds audible.  HETERODYNE BAT DETECTION WITHOUT MANUAL TUNING Firstly, Bat Detector supports the classic technique of heterodyne bat detection. Heterodyning is a simple process that operates in true real-time, demodulating the bat sounds with a carrier signal just like an old transistor radio. Most heterodyne bat detectors require you to manually tune into different species, but Bat Detector operates without any manual tuning, instead it tunes into the strongest bat signal it can hear. The heterodyne process then turns any bats sounds it hears into percussive cracks, pops and slaps, or in the specific case of leaf-nosed bats such as Horseshoe species, strange alien warbles. These are often thought of as "bat sounds" - they are not. They are sounds synthesised by bat detectors using bat sounds as a source - rhe harmonic content of heterodyned sounds is distorted and mangled, and these sounds bear literally no relationship to the sounds the bats actually made. However, operating in true real-time means that the rhythm of the bats calls is preserved, and heterodyned bat sounds - despite sounding nothing like bats - are diagnostic and distinctive, so heterodyning remains an invaluable tool for all bat workers and enthusiasts. EXPERIENCE TRUE BAT SOUNDS FOR THE FIRST TIME WITH 16x TIME EXPANSION Time Expansion was previously a very high-end, expensive option. Time Expansion in Bat Detector operates in quasi real-time, capturing small snippets of bat sound and playing them back at 1/16 speed. 16 is a number chosen for two good reasons. Firstly it brings the bat sounds down to an easy range for human hearing, the sounds generated by Bat Detector range from between 1kHz to just under 7kHz. 16x Time Expansion preserves the harmonic relationships between the bat sounds, so it is a MUSICAL transformation. The bat sounds are not only slowed down but are transposed down by exactly 4 octaves. This means if a bat calls a C#, you will hear a C#, but 4 octaves lower. You will be surprised how beautiful and musical bat sounds are when time-expanded. When used in conjunction with heterodyning, and with the accurate frequency read out on the display, bat species identification is made much easier and more reliable. FULL-SPECTRUM 384kHz RECORDINGS TRIGGERED BY BAT SOUNDS When "RECORD" is engaged Bat Detector will trigger a 5 second full-spectrum recording at 384kHz whenever it hears a bat, or at least something that it *thinks* sounds like a bat. These are not the recordings of the sounds you hear coming from the detector, but are the sounds going INTO the detector - the true ultrasonic sounds that the bats made, too high for humans to hear. You will need specialist software to examine these files after you export them from your device to a computer. DEMO MODE FOR EDUCATION AND TRAINING If you want to experience bat sounds during the daytime, in a classroom environment, or when there aren't any bats around, just turn on Demo Mode in the Bat Detector section of the settings App, and Bat Detector will loop through a collection of bat recordings from Wiltshire, England. Alternatively, if you have recordings of your own that you wish to use, create a folder called Demo in Files->Bat Detector and Bat Detector will use these in Demo mode rather than its built-in recordings.

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.