Patent ID: 8380365

Claim:
A method of indicating, on board an aircraft, an instantaneous sound nuisance level outside the aircraft, the method comprising: measuring two components of an instantaneous airspeed of the aircraft; estimating an instantaneous mass of the aircraft; during a reference flight of the aircraft, taking a plurality of external sound measurements using external microphones on board the aircraft; providing on board the aircraft a model database including a model for determining the sound nuisance level outside the aircraft, the model being derived from the plurality of external sound measurements; sampling the plurality of external sound measurements into external sound measurement samples; calculating a kurtosis of at least one of the external sound measurement samples; during a flight of the aircraft, using the model to determine an instantaneous sound nuisance level outside the aircraft based on the instantaneous measured airspeed and the estimated instantaneous mass of the aircraft; and during a flight of the aircraft, displaying the determined instantaneous sound nuisance level outside the aircraft in real time on an indicator inside the aircraft.