Table 1.
Participant Characteristics by Noise Exposure Group
| Non-Veteran | Non-Veteran Firearms | Veteran Low Noise | Veteran High Noise | |
|---|---|---|---|---|
| Age in years | 25.4 (4.2) | 25.8 (4.2) | 29.7 (4.2) | 26.7 (2.3) |
| Number of males | 7 | 7 | 6 | 15 |
| PTA (0.5, 1, & 2 kHz) – in dB HL | 6.9 (4.1) | 6.7 (3.0) | 9.4 (4.8) | 10.3 (5.6) |
| High frequency PTA (3, 4, & 6 kHz) – in dB HL | 2.1 (4.5) | 4.1 (5.0) | 4.5 (3.6) | 9.2 (4.9) |
| LENS-Q score | 4.3 (0.6) | 13.2 (2.4) | 10.8 (3.4) | 15.9 (0.8) |
| Speech in quiet (60 dB HL) | 98.3% (1.7) | 98.8% (1.4) | 97.7% (2.2) | 97.3% (2.4) |
| Speech in quiet (90 dB HL) | 96.7% (2.2) | 97.4% (2.0) | 97.7% (1.7) | 97.3% (3.5) |
| ABR wave I amplitude (μV) | 0.41 (0.11) | 0.33 (0.10) | 0.38 (0.13) | 0.30 (0.09) |
| WIN (dB SNR) | 4.0 (1.1) | 3.5 (1.1) | 4.6 (1.4) | 4.8 (1.4) |
| LDL – 1 kHz (dB HL) | 89.3 (10.4) | 88.4 (9.5) | 89.9 (8.3) | 88.3 (9.2) |
| LDL – 3 kHz (dB HL) | 84.2 (9.1) | 83.1 (8.2) | 83.1 (5.5) | 82.3 (8.8) |
| LDL – 4 kHz (dB HL) | 81.8 (9.9) | 81.1 (9.5) | 81.1 (5.9) | 80.2 (10.1) |
| LDL – 6 kHz (dB HL) | 78.0 (13.7) | 75.3 (10.1) | 72.6 (8.6) | 74.6 (10.9) |
| Report tinnitus | 0 | 0 | 1 | 14 |
| Total participants | 27 | 16 | 14 | 17 |
Participant characteristics are shown for each of the 4 noise exposure groups. Except for “number of males”, “report tinnitus”, and “total participants”, all values are group means with standard deviations in parentheses. The pure tone average (PTA) is the average of the pure tone thresholds at 0.5, 1, and 2 kHz, while the high frequency PTA consists of the thresholds at 3, 4, and 6 kHz. The score on the Lifetime Exposure of Noise and Solvents Questionnaire (LENS-Q) provides a measure of lifetime noise exposure to occupational, military, and recreational noise sources. The LENS-Q is scored on a log scale where lower scores indicate less noise exposure and higher scores indicate more exposure. Auditory brainstem response (ABR) wave I amplitude is reported for a 4 kHz 110 dB p-pe SPL toneburst. Perceptual measures include speech in quiet at 60 and 90 dB HL, the words in noise (WIN) test, loudness discomfort levels (LDLs) at 4 frequencies, and report of tinnitus. SNR is signal-to-noise ratio.