StAB - Aircraft Interior Acoustic Simulator

Aircraft Interior Acoustic Simulator

Photograph of five test subjects seated in the Aircraft Interior Acoustic Simulator Photograph of the binaural recording mannequin in a seat in the Aircraft Interior Acoustic Simulator

As part of a program to reduce aircraft interior noise in commercial transport airplanes, business and general aviation airplanes, and rotorcraft, the Aircraft Interior Acoustic Simulator (AIAS) facility was built to study human response to aircraft interior noise. It uses the interior trim and seats from current commercial airplanes to provide the visual ambience of a modern aircraft interior. The simulator is approximately 24 feet long and 11.5 feet wide and provides tourist class seating for up to 45 passengers. Noise stimuli for subjective judgment tests are presented to the test subjects through electrostatic headphones to preserve the directivity and spatial information afforded by a binaural recording system. Up to six listening stations are available. The recordings presented to test subjects are made using a binaural recording mannequin, which uses microphones located in each ear of a simulated head to record sounds as heard by an individual, and a DAT recorder. Recordings are downloaded to a workstation and digitally processed with commercial editing and analysis software. Software developed in house is used to play the sounds in the required sequence over the headphones to the test subjects

The headphone reproduction can be supplemented by 24 loudspeakers situated in the walls of the simulator outside the trim, and by further loudspeakers placed at the rear of the simulator to enhance the low frequency content of the sound in the facility. For example, three woofers and a subwoofer were used in addition to binaural headphone playback for rotorcraft interior noise simulation.