Abstract: Techniques are provided for QR Decomposition (QRD) based minimum variance distortionless response (MVDR) adaptive beamforming. A methodology implementing the techniques according to an embodiment includes receiving signals from microphone array, identifying signal segments that include a combination of speech and noise, and identifying signal segments that include noise in the absence of speech. The method also includes calculating a QRD and an inverse QRD (IQRD) of the spatial covariance of the noise components. The method further includes estimating a relative transfer function (RTF) associated with the source of the speech, based on the noisy speech signal segments, the QRD, and the IQRD. The method further includes estimating a multichannel speech-presence-probability (SPP) on whitened input signals based on the IQRD. The method further includes calculating beamforming weights, for the microphone array, based on the RTF and the IQRD, to steer a beam in the direction associated with the speech source.