Here i will first try to put my application agenda
Typically i am sampling at 8Khz rate and filtering speech components using a BPF(digital) now i have got the 0-4Khz components in which essentially <250Hz are not speech so i will eliminate them also now i am trying to find out entropy of frame and trying to mark respective frames as voice or non voice if they belong to band 250<=f<=3750 Hz
so now the problem is while i was doing this at my realtime application side there also non human sounds like birds sound or a ringing of a bell which again fall in to the frequency band i am flagging as speech
so this causes a false alarm of speech even in case of bird sound and bell ringing how to really over come this problem
what else i can try to do for effectvie speech activity detection