The term 'sound of amusement' refers to the noises made when someone is laughing or smiling. The four crossword solutions for this term are HAHA (4 letters), SNORT (5 letters), TEHEE (5 letters), and CHUCKLE (7 letters). HAHA is a sound of laughter that is often used to express joy or amusement. SNORT is a short, sharp sound made through the nose that is usually associated with laughter. TEHEE is a sound of amusement that is similar to a giggle. Finally, CHUCKLE is a low, gentle sound of laughter that is often used to express contentment.