The Active Noise Control of a Light Aircraft Cabin

The effects of aircraft noise, with respect to both passenger comfort and occupational health, have long since been realised, with many examples of sound control now implemented in commercial aircraft. However, the single engined four seater aircraft cabin is still an extremely noisy environment, which has apparently been ignored to date, especially with respect to low frequency sound reduction. Consequently, pilots and passengers are still exposed to potentially damaging noise levels, with a high dependency on the proper use of personal hearing protection. With space and weight a premium, the practical application of passive noise control methods can only provide appreciable benefit at higher frequencies. Feedforward active noise control offers a lightweight and cost effective method of reducing the low frequency noise, dominated by propeller tones. This paper, reflecting a work in progress, presents preliminary results and conclusions from the application of an active noise control system in a four seater Piper Archer.