Accoustic contamination is not considered by planners in Chile as an essential factor of the quality of life, whereas it is by the inhabitants. The harmful effects of noise are certainly recognised in legislation, but the results of this legislation are still limited. Increasing recognition of the problem has led, nevertheless, to a study of three districts of Santiago characterised by the modest or very low level of incomes and benefiting from housing grants. In two districts the principal sources of noise are internal (despite the proximity of major transport axes), limited to life styles, the quality of construction and the appropriation of the common-owned parts of the building by individuals. The third district - more affluent and in better condition - suffers from noise emanating from the city centre where it is located. However, the study shows that the perception of noise differs in relation to the age, gender and social standing of the person (the higher the level, the less the importance accorded to the negative aspect of noise). As a result the authors suggest planning for social housing at all scales and regulations to control noise from mobile sources (in a context where priority is given to the car).