Determining an empirical emission model for the auralization of jet aircraft

Aircraft noise is a major issue in urban areas and is one of the research topics 
within the FP7 SONORUS project. Current methods for determining the impact of 
aircraft noise on annoyance and sleep disturbance are based on energetic 
quantities neglecting the dynamic character of the sound. To obtain a more 
complete representation of annoyance, one should predict the audible aircraft 
sound and determine the impact of the aircraft sound on people.

In a related project at Empa, sonAIR, recordings were made of aircraft taking off and landing. These recordings were made at several positions and with several 
microphones simultaneously. Combined with cockpit data, flight path information 
and an inverse sound propagation model, this gives the possibility to determine 
the emission as function of aircraft conditions and observer angle.

An inverse sound propagation model is used to determine the emission in the 
time-domain. The obtained signal corresponds to the immission of a microphone 
flying along with the aircraft and rotating about it. The time-domain approach 
allows extracting narrowband information like tones and time-dependent variations like modulations.