Effect of background noise and memory load on listening effort of young adults with and without hearing loss

Objective: People with hearing loss often encounter difficulties in hearing under adverse conditions, such as listening in the presence of noise. Listening effort is an indicator used to assess listening difficulties in daily life. Although many studies on listening effort have been conducted in recent years, there is a notable gap in the exploration of how task load influences listening effort in young adults. This study compared the effects of background noise and memory load on task performance and subjective listening effort in young adults with and without hearing loss. Methods: The study included a group of 8 adults with hearing loss (mean age: 24.1 +/- 6.0 years) and a group of 16 individuals with normal hearing (mean age: 27.9 +/- 4.9 years). A number memorizing task was conducted, involving two types of auditory digits (either three or seven digits) presented under multi-talker babble noise conditions of signal-to-noise ratio of-5 dB [SN-5 dB] or SN +5 dB. Participants determined whether the number presented in the encoding interval matched the one presented in the retrieval interval. Subsequently, they were asked to complete a questionnaire using a Visual Analog Scale (VAS) to assess their subjective listening effort. Percentage of correct responses, reaction times, and VAS ratings were compared between adults with and without hearing loss. Results: Our results showed significant differences between the two groups in the percentage of correct responses and the reaction time under the SN-5 dB conditions, regardless of the memory load. Under the SN +5 dB conditions, a significant difference was found only in the percentage of correct responses for seven digits. In the normal hearing group, the percentage of correct responses and VAS ratings tended to decrease as the memory load increased, even under the same noise condition. Conversely, in the hearing loss group, a consistent trend could not be identified in the effects of noise and memory load on the percentage of correct responses and VAS ratings. Conclusion: These results suggest that in conditions of high noise load, young adults with hearing loss show a higher tendency for listening effort to be affected by other loads. We confirmed that for some participants with hearing loss, the task exceeded a certain level of difficulty in the SN-5 dB and seven digits condition, leading to a change in their motivation and strategy used. Future research should examine ways to control for participants' motivations.