Abstract:
The current study had the main objective of establishing the contribution to the daily recommended exposure level by the recreational activity of urban running, as a result of running in the presence of road noise and using a personal listening device. Exceeding the recommended exposure level puts individuals at excessive risk of developing noise-induced hearing loss. The hypothesis was that the preferred listening levels would depend on two independent variables: the level of the road noise and the style of the earbud used. Speech-in-noise performance was another investigated factor to observe if it could influence the preferred listening level. The performance in the speech-in-noise test was also investigated as an early indication of hidden hearing loss. Modelling of Auckland roads and their noise levels were used to determine three noise levels to be used in the study. The road noise independent variable had four levels in total: quiet ambient (control), low, medium and high noise. The other independent variable was the style of earbuds: occluding and non-occluding. Preferred listening levels were measured while participants were in a simulated urban running environment. Together, the combination of the two independent variables resulted in eight sets of simulations. Performance in the speech-in-noise test was also tested for its relationship with the preferred listening levels. Analysis of the results involved the use of repeated measures analysis of variance to identify significant interaction effects. Graphs were generated to visualize correlations. The results of the current study suggested that the majority of the runners made a negligible contribution to their daily recommended exposure level through the activity of urban running alone. Furthermore, functional studies assessing the speech-in-noise performance of the participants did not reveal any significant correlations with preferred listening levels. No early indication of hidden hearing loss was found amongst any of the runners tested. The findings of the current study involved conservative music volume settings by participants; therefore, the findings are likely an underestimation of the real noise dosages experienced by urban runners. It is a contribution to the field of research surrounding noise levels of recreational noise exposure and helps with the overall understanding of various activities that may accumulate to damaging levels.