. Author manuscript; available in PMC: 2016 Jan 31.

Published in final edited form as: Int J Audiol. 2014 Dec 30;54(0 1):S30–S36. doi: 10.3109/14992027.2014.981305

Table 1.

Cohort Demographics at Baseline

	N	%
Total	8818	100
Male	7895	90
Age (mean, SD)	44.3, 10.5
White	7736	88
Mean Noise Exposure
< 82 dBA	4068	46
82 to < 85 dBA	2015	23
85 to < 88 dBA	2104	24
≥ 88 dBA	631	7
PTA_.5123 (binaural average at .5, 1, 2, 3 kHz)
< 25 dBHL	7914	90
≥25 dBHL	904	10
Heavy/Very heavy physical demand	1618	18
HTL at 4 kHz (binaural average at 4 kHz)
< 25 dB	5112	58
≥25 dB	3706	42
HTL at 6 kHz (binaural average at 6 kHz)
< 25 dBHL	4687	53
≥25 dBHL	4131	47
PTA₄₆ (binaural average of 4, 6 kHz)
< 25 dBHL	4875	55
≥25 dBHL	3943	45
Tinnitus	1373	16
Hearing Asymmetry (≥5 dB difference at .5, 1, 2 kHz)	1570	18
Hearing Asymmetry (≥15 dB difference at .5, 1, 2 kHz or > 30 dB difference at 3, 4, 6 kHz)	466	5
Tinnitus plus PTA₄₆ < 25 dBHL	290	3
Tinnitus and PTA₄₆ > 25 dBHL	1083	12
No tinnitus and PTA₄₆ < 25 dBHL	4585	52
No tinnitus and PTA₄₆ > 25 dBHL	2860	33

Abbreviations: dBA, A-weighted decibels; HTL, hearing threshold level; PTA, pure tone average; dB, decibels, dBHL, decibels hearing level