A multi-function earplug that measures in-ear noise, standard noise dosimetry and hearing function - PROJECT SUMMARY/ABSTRACT 22 million U.S. workers are exposed to hazardous noise levels each year and approximately 16% of disabling hearing loss worldwide is work-related. In the US, despite significant regulations and the implementation of hearing conservation programs for decades, 25% of workers associate their hearing difficulties with workplace exposures. Typically, individual hearing monitoring is conducted yearly which can only provide a record of the progression of irreversible hearing loss with limited options for intervention and mitigation. Furthermore, there is limited data that links actual, real-world noise exposure to noise induced hearing loss (NIHL) making it very difficult to develop evidence-based damage risk criteria. Creare proposes to design, build, and test a multi-function earplug that will (1) provide hearing protection during activities in noisy environments; (2) record personal noise dose; and (3) monitor hearing function over time. Our integrated in-ear hearing monitoring and protection system will allow users to monitor the potential impact of hazardous noise as close to the exposure as is possible, and eventually enable real-time intervention such as better engineering controls, changes in work schedules, better personal protection or even pharmaceuticals to mitigate pre-clinical hearing damage and prevent NIHL. We have assembled an expert team that is uniquely positioned to develop this technology thanks to its active involvement in the development of innovative technologies for hearing assessment, hearing protection, and dosimetry for individuals working in noisy settings.