Listening Effort Measured Using a Dual-task Paradigm in Adults With Different Amounts of Noise Exposure
Authors: Degeest Sofie , Kestens Katrien , Keppler Hannah 
Published: October 2021

Objectives.
Excessive noise levels can result in hearing damage and/or hearing-related symptoms, thereby leading to impaired communication and, eventually a decrease in the quality of life. Moreover, in daily practice, subjects often indicate that listening in noisy situations is a challenging and often exhausting experience, even in the absence of a clinically significant hearing loss. Hence, a person’s perceived difficulty of the listening situation will also be important to consider. It has been suggested that beyond the peripheral factors, there are some central cognitive correlates of speech understanding that are essential for communication abilities. The aim of the present study was to evaluate the effect of the amount of noise exposure on hearing as measured by pure-tone audiometry and otoacoustic emissions (OAEs) on the one hand and listening effort measured using a dual-task paradigm on the other hand.

Design:
The study included 152 adults between 18 and 40 years of age. First, participants completed a self-administered questionnaire regarding the amount of noise exposure. Second, hearing status was evaluated using pure-tone audiometry and transient evoked OAEs (TEOAEs) as well as distortion product OAEs (DPOAEs). Finally, listening effort was evaluated using a dual-task paradigm, which consisted of a primary speech-recognition task in different listening conditions and a secondary visual memory task that were performed both separately and simultaneously. Based on the quartiles of their subjective estimation of noise exposure, the participants were categorized into a group with low noise exposure (lower quartile), moderate noise exposure (two middle quartiles), and high noise exposure (upper quartile).

Results:
There was no significant difference in hearing thresholds between the participants with low, moderate, and high noise exposure for each frequency of the pure-tone audiometry. In contrast, more absent TEOAEs and DPOAEs were found in the high noise exposed group. Regarding the primary speech-recognition task of the dual-task paradigm, no significant difference in speech recognition was found between the different groups of noise exposure. For the amount of listening effort, it was found that across all listening conditions subjects with high noise exposure expend significantly more listening effort compared with subjects with low and moderate noise exposure.

Conclusions:
This study is a first exploration of the effects of different amounts of noise exposure on listening effort showing that, listening effort is increased in subjects with high noise exposure compared with subjects with low and medium noise exposure. The most plausible hypothesis pertains to an effect of noise exposure on the peripheral and central auditory system, or a combination of effects on both the auditory system and the high-level cognitive functions necessary for speech understanding in the subjects with high levels of noise exposure. As such, a test for listening effort would be useful as part of a comprehensive test battery within the assessment of subjects exposed to noise.