The striking mechanism (1) of a watch includes at least one gong (3, 4, 5) fixed at one end to a gong-carrier (2) integral with a bottom plate, at least one hammer mounted on the plate for striking the gong, and a gong noise insulator arrangement (6, 7). At least one insulator part (6) of the insulator arrangement is configured to be moved in rotation by drive means (9, 11, 12) so that one U-shaped portion (16) of the insulator part comes into contact with the gong in an idle mode or is at a distance from the gong in striking mode. A rotatably mounted, opposite insulator counterpart (7) with a rod (17) is provided so that the insulator part (6) and the opposite counterpart form a clamp for imprisoning the gong in an idle mode.