A method and device to reduce the noise produced by jet aircraft engines and/or other supersonic nozzles involves the use of corrugated engine seals (30) for the secondary internal divergent flaps (14) of the nozzle (10). Such corrugated seals (30) serve not only to eliminate shock-generated noise, but also generate a counter-rotating vorticity to force low speed mixing of surrounding ambient air with the high-speed jet exhaust. Lower exhaust velocities, combined with reduced levels of the turbulent Reynolds shear stress, lead to reduction of turbulence-generated noise, including Mach wave emission.