Abstract: Exhaust muffler for sound suppression, particularly designed as an automotive muffler, which comprises a gas inlet tube communicating with a first chamber in an outer, preferably cylindrical, casing, and an exit tube coaxially aligned with the inlet tube within the casing, the inner end of the exit tube being spaced from the inlet tube and communicating with the first chamber. An imperforate boundary or baffle is positioned in the annulus between the outer wall of the exit tube and the inner wall of the outer casing, and intermediate the ends of the exit tube, the annular space to the rear of the baffle, between the exit tube and the casing, forming a second chamber which is filled with a sound absorber such as glass wool. The exit tube is perforated along the area thereof adjacent to the second chamber for fluid communication therewith.