Automated System for Digital Measurements of Ear Canal Geometry

In order to reduce risks for hearing loss among sailors, the Navy seeks new methods to accelerate widespread deployment and usage of custom earplugs. When properly fitted and worn, custom earplugs can provide consistent, reliable hearing protection. In this project, Creare is developing a new approach for characterizing ear canal and pinna geometry for prescribing custom earplugs. Our completely digital approach provides accurate and repeatable anatomic measurement for improved earplug fit, while also reducing the logistics burden currently associated with physical silicone ear impressions. During Phase I, we demonstrated that our technique measures ear anatomy very accurately (mean error less than 0.1 mm). In addition, our non-invasive approach has high repeatability and eliminates the operator and procedure variability that is typical of physical impressions. During Phase II, we aim to develop methods for balancing trade-offs among earplug comfort, fit, and performance, based on an individual’s anatomy and validated through human subject testing. Our digital technique also supports development of a database for managing, archiving, retrieving, and transmitting aural anatomy data; studying variations in anatomy across a population and the resulting impact on earplug design and effectiveness; and quantifying changes in aural anatomy that occur over time.