Skip to main content
. Author manuscript; available in PMC: 2007 Mar 21.
Published in final edited form as: J Acoust Soc Am. 2001 Jan;109(1):216–231. doi: 10.1121/1.1326083

FIG. 3.

FIG. 3

Diagram of techniques used to measure sound pressure in the ear canal and behavioral thresholds. Measurements were made with no isolation (A) and with different combinations of test devices: earplugs (B, left panel), earmuffs (C), earmuffs and earplugs together (D), a helmet and earmuffs together (E), and a helmet with earmuffs and earplugs together (not shown). Details of the attachment between the earplug, microphone, and probe tube are shown in (B), right panel; also shown is the position of the clay used to test whether the microphone was acoustically isolated from the sound field outside the ear.