Here is a link to UTUBE on which I have a video of Sarah both crying and laughing at the same time. She was crying so I turned on the camera. It happens a lot in the late day and can interrupt dinner. Once it has begun, sounds exacerbate it. I don't know how to help her. Usually I have to put her in her bed where it is quiet. Only there can she settle down. It takes about 1/2 hour or so for her to relax. Anyway, here is a little example...it starts out not bad but escalates by the end. I cough and our cat meows which moves it into full gear for your viewing pleasure:
