Waveform to event

Noise gate:
Anything below this level will not be represented on the lights.
(e.g. You have a voiceover on top of music; the music peaks at -12dB with the voice at -3dB; you want to discard the background music and keep the voiceover, so a gate of -11dB is appropriate)

Gain:
Increases/Decreases the "volume level" of the music that will be converted.  The lights will respond brighter or dimmer accordingly.
(e.g. you want to W2E a soft passage and need to boost its gain to get full intensity)

Gamma Correction:
Instead of responding linearly, gamma will make the lights respond according to a "gamma curve".  This is mostly a LED thing.  LEDs do not respond linearly, so some gamma correction is required to achieve a decent linear appearance with W2E.