We live in a world where different, complex stimuli constantly compete for our attention. The ability to perceive the appearance or disappearance of a sound (i.e., a change) in a busy environment is crucial for us to feel safe, especially in unfamiliar environments, as we often hear a change before we see it.

Change detection in the auditory domain has so far been investigated mainly with normal-hearing listeners. Brungart et al. were among the few who investigated this ability with normal hearing, as well as unaided and aided hearing-impaired subjects. The task was to identify and localize an appearing or disappearing sound in an auditory scene consisting of multiple everyday sounds, presented in the front hemisphere. The authors show evidence that hearing-impaired listeners perform better unaided than when using their own hearing aids (HA).

We developed a similar experiment, in which we first reproduced Brungart et al.’s results with normal-hearing subjects. However, our experimental design was expanded to include sounds appearing and disappearing from the back hemisphere, thus creating a more realistic setup. This experimental design was then used in a study with 14 hearing-impaired listeners to investigate the influence of hearing loss and the impact of hearing aid processing on change detection abilities. The trials in the experiment consisted of four different everyday sounds played simultaneously, with one of these sounds either appearing or disappearing halfway through the short trial. The sounds in the scene were presented either from the front, back or both hemispheres. Subjects performed the experiment unaided and with two types of HA processing. The task was to identify and localize the appearing or disappearing sound. Additionally, subjects completed a questionnaire assessing their real-life hearing loss problems so as to explore the relevance of change detection in everyday life.

Consistent with previous findings, the subjects performed significantly better in the “appear” change trials compared to “disappear” change trials regarding both sound identification and localization. However, no significant differences were observed between unaided or aided performance. Significant differences were found between aided performance in the sound identification task with two types of HA processing. Additionally, a significant correlation between one of these HA processing and the subjective assessment of real-life hearing loss difficulties points towards the importance of change detection in daily lives of aided hearing-impaired listeners.