ABSTRACT
Sounds provide an essential contact between humans and the surrounding world. Awareness of familiar sounds such as the waves at sea, footsteps of family members and music, induces reactions of recognition, pleasure and satisfaction. The harmony between normal sounds and periods of quietness is also important, particularly for music. Other sounds such as creaking floors in an empty house, sudden bangs and unpleasant music, induce alertness, fear and annoyance. Such sounds are generally referred to as noise, although this is a subjective assessment. Definitions of, as well as adverse reactions to, different sounds vary between individuals as a result of experience, attitudes and knowledge.
