background the ubiquitous use of personal music players in over-crowded public transport alludes to the hypothesis that apart from making the journey more pleasant, listening to music through headphones may also affect representations of our personal space, that is, the emotionally-tinged zone around the human body that people feel is “their space”. we evaluated the effects of emotional valence (positive versus negative) and source (external, i.e. loudspeakers, versus embedded, i.e. headphones) of music on the participant's interpersonal distance when interacting with others. methodology/principal findings personal space was evaluated as the comfort interpersonal distance between participant and experimenter during both active and passive approach tasks. our results show that, during pas