Are you being asked to write a simple vocoder?
Your question is somewhat vague and confusing, but it seems like you are being asked to determine parameter thresholds for deciding when a speech frame is voiced (has fundamental periodic component and harmonics), unvoiced or frictional (noise generated), and silent (do not encode).
It looks like you would be using the pitch frequency estimates to determine if the frame is voiced/unvoiced, and signal energy to determine if it is a silence frame.
If he said it's experimental, I think he is asking you to look at the energy and pitch content of an audio signal and see if you can see differences that will help you choose thresholds. For example, get some audio of someone speaking. When the person is vocalizing (i.e. vowel sounds like "aaaahh" and nasally sounds like "mmmmmmmm") the spectrum should show periodic components. For unvoiced sounds (i.e. short "th" "t" "s" "f" type sounds) the spectrum will look more like noise. And when there is silence, the signal should be relatively low energy. Take what you find and use that information to determine your thresholds.