Figure 16. Six acoustic cues can contribute to the perceived azimuth, whereas the left- and right HRTFs determine the elevation percept, modulated by an azimuth-dependent binaural weighting and internal priors. The strength (reliability) of a cue is indicated by line thickness. p,q,s are the partial correlations, obtained from Equations 2, 4. A, Under normal-hearing, the azimuth percept is fully determined by robust ITD and ILD cues, and the elevation percept mainly by the veridical HRTFs and azimuth. B, After acute monaural plugging (in the contra ear, c), azimuth is determined by low-frequency ITDs, and the monaural intensity and filter cues from the HSE. The resulting azimuth percept modulates the elevation percept, thereby decreasing the weight of the plugged ear. C, After training, the elevation percept is more strongly influenced by the prior (at the horizon), and less by the sensory spectral and azimuth cues.