Motorsport is a term used to cover a wide variety of sporting disciplines involving two3, three3, or four3wheel vehicles. This paper addresses one of these disciplines—motor racing, which involves vehicles with four wheels racing on the six permanent tracks (circuits) in New Zealand. These events are run according to the rules and regulations of the recognised governing body for motor racing in New Zealand, MotorSport New Zealand Inc. Motorsport noise emission is a delicate balance between retaining our viewing public and reasonable noise compliance. Sine there are no laws governing the amount of sound a person can receive by choice, motorsport throughout the late ‘70s and early ‘80s conducted a range of tests to attempt to strike a balance between the need for workable noise emission regulations and public entertainment. As a result of this earlier planning, regulations were introduced in 1987 in a format that remains largely unchanged to day. The key issues addressed by the regulations were: (1) method of measurement on site; (2) method of check measurement off site; (3) establishing a sustainable maximum level of emission; (4) spectator retention; and (5) costs controls.