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. 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. 6.

FIG. 6

(A) Objective and subjective attenuations for the earmuff/earplug combination. The solid curve is the mean objective attenuation for 12 ears (in nine subjects; shading indicates ±1 s.d.); symbols are mean subjective attenuations in eight subjects (error bars indicate ±1 s.d.). Key to symbols and vertical lines as in Fig. 5. Also shown are mean objective attenuations for earmuffs and earplugs from Fig. 5 (thin dot-dashed and dotted curves, respectively). (B) Sum of mean earmuff and earplug attenuations (dot-dashed curve and filled symbols) and attenuation for the earmuff/earplug combination (solid curve and open symbols). The results shown in this panel are based only on the ears in which measurements were made in all three of the following conditions: earmuffs alone, earplugs alone, and the earmuff/earplug combination (objective: eight ears in six subjects; subjective: three subjects). (C) Subjective attenuations for the earmuff/earplug combination (symbols) compared to the mean “bone conduction limit” ±1 s.d. measured by Berger (1983) in subjects wearing special highly attenuating earmuffs and deeply inserted earplugs (hatched area).