My daughter has started making a really loud, really high pitched squeal when she's playing. It's a happy sound, she's not upset, but it is so LOUD! She did this for a while at about 5 months (she almost 7 months now), and I decided to just ignore it....let her experiment with the sound and then move on. It worked then, she stopped the sound. Now she is doing it again...more often and louder. I don't want to discourage her from expressing herself or developping language, but I'd kinda like her to stop doing this. I never smile or laugh when she does it, and rarely even look at her, so I don't think I've given her positive reinforcement to keep doing it. Is there a way to get her to stop that she can actually understand at 7 months? Most of the time she does it while playing independently, but sometimes she'll do it when I'm holding her.