Optimal Feedback Control Formulation of the Active Noice Cancellation Problem: Pointwise and Distributed. Practical design is based on the concept of a continuously operating microphone (or group of microphones) sampling the enviornment and a speaker (or group of speakers) producing interfering waves that will cancel the noise. Applications include industrial work environments. Chapter titles are ...(1) Introduction ...(2) Previous Work on Active Noise Cancellation ...(3) Pointwise Optimal Feedback Control for ANC including both single and multiple microphone methods] ...(4) Modeling of Unwanted Noise at a Single Microphone ...(5) Distributed Optimal Feedback Control for ANC ...(6) Conclusions.