TY - JOUR T1 - Differential Adaptation in Azimuth and Elevation to Acute Monaural Spatial Hearing after Training with Visual Feedback JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0219-19.2019 SP - ENEURO.0219-19.2019 AU - Bahram Zonooz AU - A. John Van Opstal Y1 - 2019/10/10 UR - http://www.eneuro.org/content/early/2019/10/10/ENEURO.0219-19.2019.abstract N2 - Sound localization in the horizontal plane (azimuth) relies mainly on binaural difference cues in sound level and arrival time. Blocking one ear will perturb these cues, and may strongly affect azimuth performance of the listener. However, single-sided deaf listeners, as well as acutely single-sided plugged normal-hearing subjects, often use a combination of (ambiguous) monaural head-shadow cues, impoverished binaural level-difference cues, and (veridical, but limited) pinna- and head-related spectral cues to estimate source azimuth. To what extent listeners can adjust the relative contributions of these different cues is unknown, as the mechanisms underlying adaptive processes to acute monauralisation are still unclear. By providing visual feedback during a brief training session with a high-pass filtered sound at a fixed sound level, we investigated the ability of listeners to adapt to their erroneous sound-localization percepts. We show that acutely plugged listeners rapidly adjusted the relative contributions of perceived sound level, and the spectral and distorted binaural cues, to improve their localization performance in azimuth also for different sound levels and locations than those experienced during training. Interestingly, our results also show that this acute cue-reweighting led to poorer localization performance in elevation, which was in line with the acoustic–spatial information provided during training. We conclude that the human auditory system rapidly readjusts the weighting of all relevant localization cues, to adequately respond to the demands of the current acoustic environment, even if the adjustments may hamper veridical localization performance in the real world.Significance statement Plugging one ear in normal-hearing listeners disrupts the robust binaural difference cues, leading to a dramatic impairment of sound-localization accuracy in the horizontal plane. We trained plugged listeners to localize sounds in the horizontal plane through visual feedback about the true sound location. We show that the auditory system rapidly reweights the different binaural and monaural localization cues to improve performance in azimuth. Quite unexpectedly, we also found a strong degradation of localization performance in the elevation direction, even on the intact hearing side, which resulted from the training. We conclude that the auditory system rapidly adapts to current acoustic situations to optimize localization performance, even if these changes reduce performance for other acoustic environments, like encountered in daily life. ER -