The 4th Joint Workshop on Hands-free Speech Communication and Microphone Arrays (HSCMA 2014) will be held on May 12-14, 2014 in Nancy, France, immediately following ICASSP 2014 and the REVERB Workshop. It will bring together researchers and practitioners from academia and industry in an intimate and collegial setting to discuss problems of interest in the capture, enhancement, and recognition of far-field speech signals. Relevant topics include, but are not limited to, speech or speaker recognition in noisy or reverberant environments, single or multi-channel speech enhancement, dereverberation, microphone array processing, source separation, and multiple input/multiple-output (MIMO) acoustic signal processing. Interdisciplinary work that crosses multiple technical areas is especially encouraged. Demonstrations of experimental systems and prototypes are also welcome.