Figure 3 Referral Personal Attenuation Ratings. 79 of the 320 recruits (25%) were referred for follow-up testing. They are rank-ordered and presented here based on their initial PAR results. Each column presents initial PAR results (SELF-Fit), experimenter fit (EXP-Fit), and, when available, a subject re-fit (SUB Re-Fit) for an individual subject, SELF-Fit displays the original rank-ordered PAR results. EXP-Fit shows PAR results when the HPD was fit by the experimenter. SUB Re-Fit shows the results for participants who were asked to re-fit their hearing protection following the experimenter fit. Each column is representative of an individual’s results. The dashed horizontal line shows the pass/fail criterion level. All those with PARs above the line are considered representative of attaining adequate hearing protection for basic training at USMC MCRD, Parris Island. Note: PARs displayed as PAR < 0 should be interpreted as zero attenuation (i.e., suggesting minor variability in the repetition of threshold measurement). A negative PAR was obtained when the occluded thresholds were less than un-occluded thresholds. This suggests no protection from the HPD.