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 whether only three training sessions can improve spatial hearing when wearing HPDs and examined how training correlated to listening effort, auditory cortical processing, and spatial attention. Young adults were randomly assigned to a training or control group (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 versus back hemispace. The P3b significantly increased in amplitude from day 1 to day 5, but only in the training group. Sensory potential amplitudes (N100 and 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.NEW & NOTEWORTHY This study found that brief spatial hearing training partially overcomes deficits induced by hearing protection, with faster gains in the frontal hemispace. Besides perceptual learning, EEG findings suggest training-related gains in the use of spatial attention. Although performance improved over time, performance benefits were not accompanied by reductions in listening effort.