More types of laughter

Silent Laughter- A smile is at times considered a silent laughter. It is a skill that we as humans perfect over our lifetime.

Belly Laughter- This occurs when people find something absolutely hilarious, it is the most genuine type of laughter. Not only does this type of laughter put us in a good, happy mood but it is also said that belly laughter can be healthy and beneficial.

http://loreskinaite.blogspot.com/2010/04/types-of-laughter.html