Listening to music on an iPod, mobile telephone or other MP3 playing device is now widespread. Commonly taking place in public spaces, as Bull1 has noted, it envelops the listener in their own audio world. However, due to the leakage of sound, the music is often experienced by those around, as "passive-listeners". They are unlikely to have either chosen the music, or to have wanted to hear it that way. Just as music can produce positive effects, the uninvited audio intrusion brings negative effects. At the least, the intrusion can only add to the music which Slobada and O?Neill2 refer to being experienced without focussed listening?. However, in not choosing to listen to the music, the passive listener may actually find it "morally and aesthetically offensive" in accordance with Johnson and Cloonan3. This paper looks at the issue of "passive listening" for listeners who are forced to hear other peoples? choice of music. Issues such as choice and quality are examined. It will show how this degradation of the environment can ultimately lead to negative health effects for the passive listener.