A sound absorbent barrier has a sound absorbent layer disposed between a porous first cover and a second cover. The barrier also has a waterproof sound-permeable membrane between the first cover and the sound absorbent layer. The sound absorbent layer is thus protected from damage by the first and second covers and water ingress is prevented by the sound permeable membrane. The second cover may be non-porous to reflect sound waves which have passed through the sound absorbent layer back through the sound absorbent layer. Alternatively, the second cover may be porous to enable absorption of sound from two directions.