LAMPS (Loughborough and MIRA Prediction for silencers) is a personal computer based software package for modelling the acoustic performance of air induction and exhaust systems. The paper describes briefly how the software was developed and how MIRA have refined the process for the design and development of air induction and exhaust systems, primarily for the Motor Industry.The primary benefit is seen to be in the reduction of development cycle times and cost of prototype systems synonymous with more conventional iterative development processes. LAMPS is also used to develop solutions to noise problems in current production vehicles, where the cost of modifications can be very high. Two examples are included to illustrate the process. The first describes the development of an exhaust system for the Jaguar XJR 14 Sports Car whilst the second details a design change in a Jaguar V12 air induction system.