The housings are designed to attract flies to encourage spiders to build their webs at the optimum distance from the optical microphone.

Unlike a conventional pressure difference microphones an optical microphone focuses on the individual strands of silk and visually converts the webs movement in to sound, completely eliminating background noise.

Spider amplifier optical microphone detail

The leather clad units house a powerful unbalanced loud speaker to allow the speaker to visually vibrate and swing when triggered.

Spider amplifier suspended speaker detail

Alternative design probes were intended to be used in different situations.

Spider amplifier optical microphone