Three types of two-layer porous pavements have been tested on an urban road with a speed limit of 50 km/h. Annual measurements including noise, permeability, texture and air voids have been performed from the pavements were new in 1999 and until the top layers were worn down in 2007. High noise reductions of 4.5 to 6.0 dB - relative to a dense asphalt concrete reference pavement of the same age - were achieved from mixed traffic when the pavements were new. The noise annoyance gradually diminished as the pavements grew older due to clogging and ravelling. The pavement with 8 mm maximum aggregate size in the top layer had lower noise reduction than the two with 5 mm maximum aggregate size when the pavements were new, but over the entire test period the 8 mm pavement had the highest noise reduction.