Vehicle cab noise suppressing system

A vehicle cab noise suppressing system includes a cab interior panel (16) having an opening (31, 33) exposed to acoustic noise in the cab, an acoustic resonator chamber (18, 20), and a conduit (52, 54) communicating the resonator chamber (18, 20) to the opening (31, 33). The resonator chamber (18, 20) is formed by a plurality of walls (30 - 40; 42 - 50) which are spaced apart from the interior panel (16) and which are formed by a second panel (14). A third panel (60, 62) cooperates with the walls (30 - 40; 42 - 50) to enclose the resonator chamber (18, 20). The chamber volume and the diameter and length of the conduit (52, 54) are chosen so as to acoustically tune the chamber to a noise frequency in the cab and thereby reduce noise in the cab.