Brief training can reduce spatial hearing deficits when wearing hearing protection

Hearing protection devices (HPDs) impair situation awareness, which includes spatial hearing because HPDs disrupt the use of spatial cues used to define sound location. After disruption, spatial hearing improves after several weeks, particularly with training. This study tested if only three training sessions can improve spatial hearing when wearing HPDs, and examined training correlated to listening effort and auditory cortical processing and spatial attention. Young adults were randomly assigned to training or ≥tact control groups (n=25/group). On days 1 (baseline) and 5 (post-training), both groups performed a spatial hearing task, and a spatial attention task with EEG recording. On days 2-4 the training group received performance feedback after each spatial hearing trial. Spatial hearing measures were absolute localization error and percent of front-back confusions, while listening effort was measured by self-reported fatigue and mood, as well as pupillometry. Event-related potential methods quantified auditory (N100, P200) and association (P3b) cortical processing. Training reduced front-back confusions and improved sound localization with HPDs, with smaller improvements in controls and some transfer without HPDs. Training improved exponentially over days, with faster improvement for sounds in the front vs. back hemispace. The P3b significantly increased in amplitude from day 1 to day 5, but only in the training group. Sensory potential amplitudes (N100, P200) and listening effort measures did not significantly vary from days 1 to 5. These findings show that brief training substantially reduces HPD impairments on spatial hearing. In addition to perceptual learning, training may also improve spatial attention.