Noise from a plane is caused by two things: by air passing over its airframe, the fuselage and wings, and by the engines.

When air passes over the aircraft's airframe, it causes friction and turbulence, which results in noise.  Planes land with their flaps down which creates more friction and produces more noise than a plane with its flaps up.

Engine noise is created by the sound of the engine's moving parts and by the sound of air being expelled at high speed.  Most of the engine noise comes from the exhaust or jet behind the engine as it mixes with the air around it.

The level of noise generated varies according to aircraft size and type, and can differ even for identical aircraft depending on factors such as weather conditions. Aircraft engines do not produce as much lift in hot weather when the air is less dense, this may result in the aircraft flying at a lower altitude during takeoff. Other factors may include weight of the aircraft, including passengers, baggage, cargo, and the amount of fuel onboard. In addition the direction in which the aircraft is travelling may affect the noise generated over a particular location. at Edinburgh Airport aircraft take off either to the east or the west of the runway dependant on wind direction.The majority of the time (70%) aircraft will take off to the west.