A device (1) for lowering flow noises has opposed first and second connection pieces (2, 3), and outer and inner sleeves (4, 5) between the connection pieces. A radial collar (6) is between the sleeves (4, 5) and forms separated volume chambers. Openings (11) in the inner sleeve (5) connect the volume chambers to a line space (13) enclosed by the inner sleeve (5). A sealing ring (15) at the free end (14) of the collar (6) defines a ring cap with a lateral surface (21) that reaches over the collar (6) and seals against the sleeve (4, 5) adjacent the free end (14) of the collar (6) and that has a surface (23, 26) that seals against either an end face (25) of the collar (6) or a side surface (28) of the collar (6) extending parallel to the radial collar (6).