This book is presenting the beamforming techniques for speech separation using microphone arrays. The primary aim of the project is to increase the speech recognition accuracy by minimising the signals other than desired signalIn a multiple speaker environment, speech of a speaker of interest is contaminated by interference and noise, leading to low intelligibility for human hearing and for further advanced processing such as speech recognition. Adaptive beamforming techniques have theoretically shown great potential for extracting the speech signal of interest.