Will-be-set-by-IN-TECHThis wireless link can be used to synchronize the processing performed by both hearing aids or to exchange the signals received at each side.The latter allows the use of multi-microphone noise-reduction algorithms such as BSS-based noise reduction algorithms.The perceptual advantages of a binaural processing over independent non-synchronized hearing aids have been extensively documented by (Moore, 2007;Smith et al., 2008;Van den Bogaert et al., 2006).These perceptual studies showed subject preference for those algorithms that preserve the direction of arrival (localization cues) of the target and interfering signals.Hence, this chapter addresses the problem about the preservation of the localization cues in noise-reduction algorithms based on BSS, whose main target application is a binaural hearing aid.This chapter includes an overview of the state-of-the-art BSS-based noise-reduction algorithms that preserve localization cues.This overview describes in detail five BSS algorithms to recover the localization cues: BSS constrained optimization (Aichner et al.,