Custom Noise Braker® test data sheets
The data provided below is from tests done on Custom Noise Brakers® made by our lab. Individual impressions are required. Standard or stock type earplugs will vary in attenuation (view test data for standard plugs) as well as custom units made by other labs. Our proprietary "Hocks Noise Braker® filter" is used in other products and while attenuation data should be similar, the test data on this site is for Hocks Noise Braker® units only.
The following letter is from Jack Vernon, Ph.D., and is a reproduction of the original letter. It shows how much sound the
Noise Braker® blocked at different decibel levels.
The next two images are reproductions of a letter from Paul L. Michael. It shows the data
that was used in obtaining the NRR for both custom made Noise Brakers® and custom made solid state ear plugs.
