In a narrow sense, noise can be considered as unwanted sound and refers to cases where the potentially affected person is not intentionally listening. People who choose to listen to music or use personal music players can be exposed to loud sounds, which they do not consider as noise. An involuntary bystander may nevertheless be distracted and annoyed and may rightfully, call noise what is sound in his neighbour"s ears. In a broader sense, noise is often used as a synonym for sound.