J.C.
Sounds like your girl has discovered her voice and the power of her voice. I bet she will be an early talker too. This is completely normal she is exploring what sounds she can make. Just happens to be at a loud level of exploration. You can try ignoring the screaming when you know for sure it is not a safety issue. The whiny and clingyness is also normal, at 6mo babies go thru a separation anxiety stage and want mom and dad constantly. This will pass in a month or two. In the mean time you will not be 'spoiling' her by giving her attention when she wants it. I nannied a girl who was a terrible screamer at 6mo! Her parents and I thought we would go deaf! So I can commiserate. We would ignore the screaming if we knew for sure she wasn't hungry, didn't needed a diaper change, and was safe. She didn't like her crib (she liked her co-sleeper playpen to sleep in)so we would sometimes put her in there where we knew she was safe and would walk out of the room. This usually worked, because after a few times she caught on that when she stopped screaming we would come back in the room and take her out. By the age of 1yr she had pretty much stopped the screaming and was working on forming words. I bet your girl will be the same way!