[Ailae]

I guess you could, but why would you?

You're creating a function just to call another function that does all the stuff (I presume). As long as your PVPSound table is local, the UpdateSoundEffectEngine function will also be local and you can set it as the script handler.

function PVPSound:UpdateSoundEffectEngine(elapsed)
-- stuff goes on here
end
 
PVPSoundEffectSoundEngineFrame:SetScript("OnUpdate", PVPSound.UpdateSoundEffectEngine)