What you will hear, should you click "Play" above, is the sound of frequency-shifted bats singing the Batman theme, by means of a sampler and keyboard:
Bats produce sounds that are not audible to human ears. First these ultrasounds were digitally reduced to frequencies that are audible. Then the different batsounds were assigned different keys on a keyboard. On this keyboard - the only real Bat-Organ - Ulrich Seidel played the Batman Theme (Neal Hefti, 1966). The video clip was compiled by Sándor Seuntjens using footage from Batman (film, 1966), Batman (animated television series, 1992-95), and National Geographic (natgeowild.com).