Background: Hearing loss is linked to frailty, walking difficulties, and an increased risk of falling. Difficulties in walking, i.e., a reduced walking speed, decreased step length, as well as a higher variability in stride time, were already described for hearing impaired subjects. The interaction of this changed motion performance, i.e., it could also be considered as noise, on speech understanding remains unclear. Dedicated speech tests are usually performed with listeners seated in an acoustic laboratory with highly controlled conditions, although daily life often challenges listeners with additional tasks while perceiving speech. Previous investigations in virtual reality walking setups testing speech understanding in noise or speech background proofed the impact of physical load on cognitive resources and thus, speech perception in acoustic complex environments.

Rationale: Thus, we here investigated the effect of walking on the perception of monosyllabic words either with or without hearing loss compensation with hearing aids.

Methods: Speech perception thresholds, i.e., %-correct, for monosyllabic words (Freiburger speech test) were collected in a classical audiological laboratory setup with subjects seated in front of a speaker as well as in a dual task guided walk with subjects carrying the speaker for testing in a backpack. All listeners (n = 24) were hearing impaired and completed both tasks wearing hearing aids either without or with an amplification compensating for their individual hearing loss. Hearing aids were equipped with integrated Inertial Measurement Unit (IMU) sensors. Data collections were App-based, and gait patterns were extracted from accelerometer data using the ear gait package (https://pypi.org/project/eargait/).

Results: For all listeners speech perception thresholds significantly declined during the dual task compared with the lab situation either with or without compensated hearing impairment. While speech perception thresholds improved for all listeners in both situations with compensated hearing loss, thresholds improved less for listeners during the dual task than during the laboratory testing. Further, gait patterns revealed longer stride times, decreased step length, and reduced gait velocity comparing walking with completing the dual task, i.e., walking and testing speech perception thresholds.

Conclusion: Motion activity such as walking appears to demand additional cognitive load while seeking to understand speech resulting in less beneficial hearing aid compensation compared to focused and undistracted listening. Further, besides speech perception thresholds, also gait patterns deteriorate to a state associated with walking difficulties. In conclusion, hearing aid compensation success not only depends on the hearing impairment of an individuum but also the cognitive load in addition to speech understanding.