The basic components of the electro-acoustic bottle, or eBottle, are a bottle (or a resonating closure), a microphone, a loudspeaker, and an amplifier. A schematic view of the system is shown in the figure below. The microphone is placed inside the bottle and the gain of the amplifier is set so that the system starts oscillating or feeding back. This oscillation is due to acoustic feedback.

The oscillation frequency is mainly determined approximately by the size of the bottle: small bottle - high pitch, large bottle - low pitch. As can be guessed from the figure below.

The birth history of the E-bottle consists of a chain of coincidences and insight, acted out by Jaakko Prättälä and Henri Penttinen. The plan was to record different sound sources filtered with a bottle, so that a microphone was placed inside the bottle. By accident during the process, it was found out that while monitoring rhythmic hitting of a bottle through a loudspeaker, the system started feeding back. (Longer version coming...)