trigger something with audio in a dsp network

[Morphoice]

is there a way to trigger something, e.g. an envelope, with audio in a dsp network?
i'm trying to add a short sound (bleep, noise) when a certain threshold is passed (like at the opening of a gate) and again when it closes after a short release time.

the point being automatically adding a short mic noise at the start and end of a spoken line, like in a walkie talkie simulation. what nodes would I use to achieve that?

[Morphoice]

Also how do I make something louder with a gain node just going to 1 and not above?

[ccbl]

@Morphoice if you right click, or maybe double click the slider, you can manually set the maximum and minimum to include positive gain.

[Morphoice]

@ccbl aye thanks! any advice on the first issue?

[Lindon]

@Morphoice look at the envelope follower...

[DanH]

@Lindon @Morphoice and the control nodes, in particular the bang node