I'm not sure exactly why these are two different options, they do basically the same thing, however Noise Gate does not have a RMS option and it is extremely rigid. Expander is pretty flexible, however because it doesn't have a open/close threshold you can't nail down more specifically when it opens AND closes, instead you have a pseudo value which doesn't do exactly what you're looking for.
Noise gate would work better if it had a RMS value (for open and close, especially close) and Expander would work better if it had a open/close threshold. Neither do exactly what they should or maybe they do in a too literal fashion, both could be combined into the same filter and work better.
I made a post on this a few years ago and it was never updated, for the longest time I was using a Teamspeak relay server as it has better voice activation for talking.
Noise gate would work better if it had a RMS value (for open and close, especially close) and Expander would work better if it had a open/close threshold. Neither do exactly what they should or maybe they do in a too literal fashion, both could be combined into the same filter and work better.
I made a post on this a few years ago and it was never updated, for the longest time I was using a Teamspeak relay server as it has better voice activation for talking.