Voice input silence detection (personal API warper)

I wonder how Google Voice Input works code-wise? I have got my own API wrapper in bash and I am trying to mimic the voice input feature. That is, when the user stops talking for a short period of time, then the voice record quits and the software proceeds to the request.

As per the demo on YouTube from (MadeByGoogle), my manual stopwatch gave values within the range from 1.4 to 1.8 seconds (when the user stops talking and the AI responds).

I am guessing, though, that those stopwatch marks refer to more than just the silence detection mechanism (it includes submitting the voice record for further post-processing of the input by Google server-side magic for speed).

What is a reasonable amount of time a typical user may expect or wish to be in the silence detection feature?

I thank you all in advance.