The Solution
We carried out a dedicated measurement campaign inside the aircraft cabin based on 2 series of tests: on ground (using loudspeaker or during run-up tests) and in flight (normal configuration in terms of flight level and aircraft’s speed) :
- Determination of the Sound Intelligibility Level (SIL)
- Reverberation time measurement inside the passengers’ compartment (executive area, first class, guest …). in order to determine the reverberation level in the aircraft
- Evaluation of acoustic absorption coefficients (re. trim panels, seats and other equipment in the aircraft cabin).
- Airborne sound insulation measurement between several compartments in the aircraft and external airborne sound, using sound pressure measurement and broadband loudspeaker (difference in Decibels between emitted and received noise levels).
- Noise mapping based on sound intensity measurements in the vicinity of noise radiating surfaces inside the passengers’ compartment. Such noise maps allow to visualize the location of acoustic weakness areas along the cabin (low insulation or defaults) and the identification of noise paths linked with the internal air conditioning system.
At the end of the work carried out Metravib team supplied a complete series of results validating the acoustic comfort inside the considered aircraft cabin, and some proposals have been made for further improvement upon request.
