This article reports the results of a survey trying to evaluate different aspects related with ambient noise and its effects on selected urban communities. A total of 263 residents in 5 different neighbourhoods of the city of Valencia were interviewed. For each one of the neighbourhoods, level of ambient noise were independently registered during 24 hours during some days of a week. 40% of the interviewees reported having some difficulty for getting to sleep and 59% of these with difficulties identified the traffic noise as the causation. Also, 49% reported to awake sometime during the night (24% of them pointed to the traffic noise as the major cause). All these problems were reported more frequently in the neighbourhoods with a greater level of ambient noise. The probably high number of people affected by sleep disturbances related with ambient noise during the night makes necessary to adopt adequate correcting actions.