The invention of the jet engine and its development during World War II as the propulsive system for fighter aircraft led aircraft designers in the late 1940s to investigate its use as the power plant for civil air transports. The aim was improved speed, economics, and efficiency over that of slower propellor-driven aircraft. However two major problems existed, (a) its high fuel consumption, and (b) its noise at full take-off power. Innovative University jet noise research in the UK in the late 1940s and early 1950s quickly led to strong industry--university collaboration. This resulted in the development of the corrugated or lobed nozzle for jet noise reduction and later to the introduction of the bypass engine achieving significant reductions in both specific fuel consumption and jet noise reduction. The experiments by R. Westley and G. M. Lilley at Cranfield and by Professor E.J. Richards and A. Powell at Southampton University, Professor Sir James Lighthill's theoretical studies at Manchester University, and the skill of F.B. Greatrex and his team at Rolls-Royce all contributed to this successful revolution in civil aircraft design. The paper discusses the rapid development of this early jet noise research and the corresponding complementary work in the USA.