Talking of filthy laughs I was at a pedestrian crossing at Knightsbridge many moons ago and heard the filthiest laugh I looked round and upwards and I was gobsmacked It was the late POW with a couple of her friends heading for Harvey Nicks The demure Shy act never rang true after that
My laugh was described by a comedian as '... not a sound you want to hear at night when alone in a haunted house...' I was laughing too much to be insulted unfortunatly.
I think there's a video in animals and nature in which I both speak and laugh Rowan, it scared Jack as I apparently sound like her... so I'll answer for her and say Jack laughs like 'manic, serial killing ghost of a dead witch'... It's nice to be helpful.
I think it depends where I am. At home with my mother and sister, it will be full on hysterics at the slightest thing where we all end up crying and too weak to move. In less appropriate circumstances I have been known to laugh really quietly until tears run down my face and an involuntary snort escapes.
More silly girly giggle I'd say, I tend to laugh quite quietly though I tend to end up shaking and tears coming out of my eyes then and end up looking like a panda as I've never been able to find a mascara/eyeliner that is me proof.
Mine is more of a hahahahaaaa laugh, with emphasis on the haaaa. No snorting but goes from hahahahaaaa to breathless hysterics at the mere sight of Johnny Vegas.