I want to determine whether a speech frame is voiced/unvoiced. Out of many methods found while searching, one method said find energy of the frame and if it is above a certain threshold, mark it as voiced. Now, my question is how should I determine this 'threshold value'? Is it by trial and error or are there any set of rules?
In my attempts, I resorted to a simple idea of looking at the energy plots and setting a threshold value accordingly. It served me well, but I want to know whether it was just beginner's luck.