Mean estimated distances (left) and interindividual variation in the estimated distances (right) as a function of nominal source distance (abscissa) and nominal source azimuth (shades of gray) for the subsets: Head Tracking – Loudness Normalization (HTNorm), Head Tracking (HT), Static – Loudness Normalization (STNorm), and Static (ST). The error bars in the mean plots (left) display 95% within-subjects confidence intervals [50, 51], based on the error term of the respective distance main effect. The box plots (right) show the median and the (across participants) interquartile range (IQR) per condition; whiskers display 1.5 × IQR below the 25th or above the 75th percentile and outliers are indicated by plus signs.