Limitations of the Three-Microphone Signal Enhancement Technique
Donald K. Nance, Krish Ahuja · 45th AIAA Aerospace Sciences Meeting and Exhibit · 2007
The so-called three-microphone method is a signal enhancement method that allows one to educe a signal buried in extraneous noise using the coherence between each pair of microphones in a three microphone system. This method holds considerable promise for separating core noise from jet-mixing noise provided the limitations of the three-microphone method are well understood. A detailed uncertainty analysis of the three-microphone method is carried out in order to determine error bands for calculated data. The behavior of the method when multiple correlated sources are present is studied via numerical simulations and model-scale experimentation in anechoic facilities. Results from this numerical-simulation and model-scale testing form the backbone of this paper. Conclusions concerning the practical usage of the limitations of the three-microphone technique are drawn.