The term 'Sound of Breaking Up' can be summarized by two crossword solutions: HAHA (4 letters) and HEEHEEHEEHEEHEE (15 letters). Both of these solutions refer to the sound of laughter, which is often associated with breaking up. Laughter is often seen as a way to cope with difficult situations, such as a break-up, and can be used to express relief or joy. The shorter solution, HAHA, is a more common expression of laughter, while the longer solution, HEEHEEHEEHEEHEE, is an exaggerated version of laughter, often used to emphasize the emotion.