My prgoram need to record people's speech via microphone.
(only in one or two minutes)
And if he haven't speak,there is only backgroup noise.
at this time I didn't want to record the sound file,
I want is When he start to say,then I start record the file.
so how can i know if he starts to speak ,
and how can i kown if he stops?
another question: how can i filter the background noise?