 A sound up to four seconds long could be recorded on the looped tape and the ten playback heads would then read the information with different delays, according to their (adjustable) positions around the disk.A separate amplifier and band-pass filter for each head could modify the spectrum of the sound, and additional feedback loops could transmit the information to the recording head.The resulting repetitions of a sound occurred at different time intervals, and could be filtered or modified through feedback.