[com2kid]

Been there, implemented it, it works well enough.

Better solutions are possible but even tiny models are capable of being given a partial sentence and replying with a probability that the user is done talking.

The linked repo does this, it should work fine.

More advanced solutions are possible (you can train a model that does purely speech -> turn detection probability w/o an intermediate text step), but what the repo does will work well enough for many scenarios.