Design of immersive binaural surround systems requires an understanding of the perceptual cues for sound source localisation. Any source at a given angle of incidence to the head will create subtle time and level difference cues at the ears and is subject to spectral shaping due to the pinnae. These cues are embedded in the Head Related Impulse Response (HRIR). For headphone reproduction of 3-D audio, filtering a source signal with a unique pair of HRIRs and presenting these filtered signals over headphones will ideally give the listener the impression that the source is located outside of the head and in the direction dictated by the filters. This process, known as binaural synthesis, has several drawbacks. First, HRIRs are unique for each listener, and the capture of large datasets of HRIRs is expensive and time consuming. As yet there is no assured method for selecting ‘near match’ HRIRs for an individual and generic HRIR sets are known to produce sound localisation errors, including front-back reversals, and lack of externalization. Adaptive HRIR processing based on head-tracking has been shown to improve front back errors, but further work is required to quantify the effect on height perception. In this regard, the proposed PhD will look at new methods of HRIR measurement and characterization that will exploit recent advances in head-tracking technologies with a strong emphasis on dynamic source-listener scenarios and height perception.