The term 'Laugh Sounds' can be broken down into two crossword solutions: HOS (3 letters) and HAHA (4 letters). HOS is an acronym for 'Heard Of Sound, ' which is a type of sound effect used in film and television to create the illusion of a live audience laughing. HAHA is an onomatopoeia, which is a word that imitates or suggests the source of the sound it describes. In this case, HAHA is used to represent the sound of laughter.