Garageband Noise Gate won't click
Garageband 10.1.0
CONTEXT
I'm recording vocal audio using condenser mic. I've found the noise gate option, activated the audio units in the preferences, added a auhipass filter just to ensure it was available, but noise gate will not click.
QUESTION
How do I activate the noise gate?
What parameters must be in place for the noise gate to be available?
GarageBand 10, OS X Yosemite (10.10.4)