Source: Masters Abstracts International, Volume: 50-04, page: 2394.

Advisers: Mark B. Russi; Peter M. Rabinowitz.

Objectives: The specific objective of this research was to explore, in the setting of a worksite intervention study of a new hearing conservation technology allowing workers to monitor their noise exposure on a daily basis, how the study subjects were using the technology. This information can be used to evaluate how technology and user interaction affect personal protective equipment design, making the equipment more efficient and user-friendly. Usability considerations, when integrated into the product development process at an early stage, can increase the efficacy of an intervention trial, improve user satisfaction, yield significant cost-savings, and minimize loss to follow-up. It is believed that hearing protection device tolerability and usability along with comfort will strengthen occupational hearing conservation and universally reduce the rate of noise induced hearing loss.

Methods: The ongoing study involves workers recruited in industrial facilities to receive the intervention consisting of a small dosimeter ("Quiet Dose") fitted inside of a hearing protector designed to provide daily noise exposure monitoring. Subjects used the QuietDose on a daily basis during the study follow-up period. A baseline and annual survey was created and distributed to the employees to measure possible experiences using the Quiet Dose device. Reported issues regarding usability were measured qualitatively annually from 2008--2010. Employees were asked to think about future usability improvements that would make the device more user-friendly. It was necessary to quantify how frequently subjects used the QuietDose (i.e., the number of downloads) and the impact of how the subjects perceived the unit in reference to overall usability. A bivariate model was designed to compare the usability characteristics of the QuietDose to employee downloading status (i.e., distinguish the predictors of whether individuals continued in the study or stopped downloading). After analyzing the bivariates, a multivariate model was created which only included covariates with a p-value <.10. Correlations between downloading status and the various usability characteristics of interest were investigated using a Pearson's Correlation Coefficients model. Finally, sixteen in-depth focus groups were conducted to further explore common themes regarding the usability of the technology.

Results: The results of this study indicate that a lengthy download time, the need to start or stop the QuietDose, and/or ear discomfort influenced whether individuals chose to remain in the intervention trial. Some usability characteristics were more significant predictors than others (i.e., stopping or starting the unit, p<.05) of whether an employee stopped downloading during the study.

Conclusion: Recent technological advances in hearing protector devices give us the ability to record noise exposures inside of hearing protectors, and to log such noise data on a daily basis. Now that we know this approach leads to a reduction in noise-induced hearing loss over time, we as researchers need to understand how to improve the efficacy of such intervention trails to reach a vast number of workers that are affected. This study is an attempt to supplement prior research by Rabinowitz et al. (2010) and confirms the significance of the ongoing intervention effect.