Evidence of hearing loss in a 'normally-hearing' college-student population

Abstract

We report pure-tone hearing threshold findings in 56 college students. All subjects reported normal hearing during telephone interviews, yet not all subjects had normal sensitivity as defined by well-accepted criteria. At one or more test frequencies (0.25-8 kHz), 7% of ears had thresholds ≥25 dB HL and 12% had thresholds ≥20 dB HL. The proportion of ears with abnormal findings decreased when three-frequency pure-tone-averages were used. Low-frequency PTA hearing loss was detected in 2.7% of ears and high-frequency PTA hearing loss was detected in 7.1% of ears; however, there was little evidence for 'notched' audiograms. There was a statistically reliable relationship in which personal music player use was correlated with decreased hearing status in male subjects. Routine screening and education regarding hearing loss risk factors are critical as college students do not always self-identify early changes in hearing. Large-scale systematic investigations of college students' hearing status appear to be warranted; the current sample size was not adequate to precisely measure potential contributions of different sound sources to the elevated thresholds measured in some subjects.

Figure 1

Threshold sensitivity (mean +/− S.E.) did not significantly differ as a function of ear (right versus left) in the total subject sample (1A), or in subsets that were limited to just male (1C) or female (1D) subjects. When average thresholds (right and left ear combined) for male and female subjects were compared (1B), male subjects had significantly (p<0.05) worse threshold sensitivity than female subjects at all test frequencies (0.25, 0.5, 4, 6, and 8 kHz). One, two or three asterisks indicates statistically significant difference at the 0.05, 0.01, or 0.001 level respectively.

Figure 2

Threshold sensitivity (mean +/− S.E.) significantly differed at only 6 kHz and 8 kHz as a function of reported PMP use in both male (2A) and female (2B) subjects. Male subjects that reported use of PMPs had significantly worse threshold sensitivity than male subjects that did not report use of PMPs; the opposite relationship was observed in female subjects. Threshold sensitivity (mean +/− S.E.) did not differ as a function of reported impulse noise exposure in either male (2C) or female (2D) subjects. One asterisk indicates statistically significant difference at the 0.05 level.

Figure 3

All ears were individually scored as “Pass” or “Refer” with an ear scored as a “Refer” when thresholds were worse than the “Pass” criterion at any frequency from 0.25 to 8 kHz. Thresholds within Pass and Refer categories (mean +/− S.E.) are shown for pass criteria of ≤25-dB HL (3A), ≤20-dB HL (3B), ≤15-dB HL (3C), and ≤10-dB HL (3D). As the pass criterion was lowered, the number of ears classified as referrals increased.