Haunting sounds are often associated with the supernatural and can be used to create a spooky atmosphere. The term 'haunting sound' can refer to a variety of noises, such as a MOAN, an ECHO, or a BOO. A MOAN is a low, mournful sound, usually made in response to pain or sorrow. An ECHO is a sound that is repeated after being reflected off a surface, such as a wall or a canyon. Finally, a BOO is a loud, sudden exclamation, usually made to startle someone. All of these sounds can be used to create a haunting atmosphere.