A device for reducing the jet noise of a turbine engine includes an outer cover having an inside wall defining the outside of an annular passage for passing a bypass stream from the engine, the wall of the outer cover including a plurality of microjet circuits, each including intakes for taking a gas stream from the bypass stream flow passage and leading to a single feed duct, which in turn opens out into the trailing edge of the outer cover via at least one ejection grating suitable for splitting the intake gas stream into a plurality of gas streams of right sections of dimensions less than a right section of the feed duct.