It was interesting to study the various attenuation profiles of customized hearing protection devices.
How does attenuation vary with frequency?
How does a filter with uniform response to attenuation behave?
What is the maximum and minimum attenuation that can be expected of a protector?
This document covers three categories of filters: filters with controlled air flow, waterproof filters, and filters with uniform response.
Once the standard profiles have been established, a second part will cover the minimum and maximum attenuation measurable under CAPA (system to measure the effectiveness of hearing protection earplugs).