Sennheiser Element – Laser Drum Microphone System
The laser drum microphone measures the physical vibration of the drum head directly. We use this to run the sidechain of a standard gate to achieve excellent bleed suppression and reduced false triggering. This allows the microphones to stay off until the drum is physically hit, giving a tighter, more controlled drum sound.
…but most importantly, we did it with lasers.
Noise-gate diagram by Iain Fergusson. Licensed under the Creative
Commons Attribution 3.0 Unported license. (via Wikipedia)