A nacelle exhaust nozzle having a deployable noise-reducing component is described. The noise-reducing component includes an annular perforated sleeve coinciding with the inner nacelle loft line and circumscribing a mixed exhaust gas flow exiting the nacelle. The annular perforated sleeve is radially spaced apart from of a displaceable wall of an inflatable envelope that is displaceable between a deployed position, wherein noise-reduction is active, and a retracted position, wherein noise-reduction is inactive. When the inflatable envelope is pressurized, portions of the displaceable wall project through openings in the perforated sleeve and into the exhaust gas flow to form a rough surface at the loft line which causes a reduction in noise level. The portions of the displaceable wall that project through the openings in the perforated sleeve when the inflatable enveloped is pressurized include a plurality of dimples formed on the inner wall and forming the rough surface.