The problem of enhancing speech degraded by uncorrelated additive noise, when the noise speech alone available, has recently received much attention. Beamforming is one possible method of speech enhancement, because, the beamformer minimizes the output signal power but maintains signals from the desired direction. Beamforming techniques basically approach the problem from a spatial point of view. A microphone array is used to form a spatial filter which can extract a signal from a specific direction and reduce the contamination of signals from other directions. In this paper we survey some Beamforming techniques used for minimize the noise power in the output signal.