When my DS squeels- i squeel back at him and we have a squeel convo and he gets it out of his system and doesnt do it anymore- for a while anyway!!

But im not sure that his squeels are quite the same as what you describe... but he does seem to enjoy himself when he does it- so i make a game out of it!
We do that. DD is 4 months old and has just found her voice so it is practice time

It is just a learning thing for them - to practice talking, seeing reactions, social interaction etc. Discipline is not something they understand at 8 months. Time out is for mummy - the baby will have no concept of why they are in the room. There is no cause / effect interpretation no matted how intelligent they are. And privileges at this age don't exist. They are purely essential living requirements, not things like their mobile phone or internet time.

It is usually a phase and with DS it did go away after about a month. Just try to ignore it. Go to another room or go the complete opposite and turn it into conversation and social interaction time. Another tip is to scream back increasingly quieter. They love to imitate and imitating the quieter noise is great