Noise control in three-dimensional propagation

This paper presents an investigation into the process of noise cancellation in a three-dimensional non-dispersive (linear) propagation medium using a multiple-source system configuration. The process of field cancellation is considered from a frequency-domain viewpoint. The degree of cancellation is analysed in relation to source-related and geometry-related parameters of the system leading to a three-dimensional description of the pattern of cancellation and reinforcement in the medium and merits of the system design. Moreover, the effect of implementation errors on the physical extent of cancellation and the extent of error tolerances, for consideration in the process of design of the system, are analysed and discussed.