A sound depressing exhaust means for a pneumatic power tool with a substantially cylindrical housing (10) and a vane motor (11) with exhaust port means (23), has an annular casing (41) surrounding a portion of the housing (10), and four expansion chambers (31-32, 34, 36, 39) arranged in series and combined with four flow restrictions (33, 37, 30, 35) and a sound trap (38). All of the expansion chambers are annular and located concentrically relative to the tool housing (10), and one of the flow restrictions has an annular screen (37) separating two of these chambers (34, 36). The last two of the expansion chambers (36, 39) in the exhaust flow direction contain high frequency absorbing elements (43, 44) of foamed plastic.