Table 1.

Descriptive characteristics of low and high workplace noise exposure subjects.

Variable	All (N = 5205)		High exposure level (N = 1041)		Low exposure level (N = 4164)		P
	n	%	n	%	n	%
Gender
Male	4880	93.76	976	93.76	3904	93.76	1.000a
Female	325	6.24	65	6.24	260	6.24
Age, years	37.23 ± 9.11		37.06 ± 9.20		37.27 ± 9.09		0.500b
<30	1292	24.82	263	25.26	1029	24.71	0.502a
30–45	2638	50.68	532	51.10	2106	50.58
>45	1275	24.50	246	23.63	1029	24.71
Exposure time, years	5.31 ± 5.28		5.25 ± 5.17		5.33 ± 5.32		0.680b
<3	1996	38.35	402	38.62	1594	38.28	0.231a
3–10	2325	44.67	484	46.49	1841	44.21
>10	884	16.98	155	14.89	729	17.51
Threshold [dB (A)]	23.32 ± 10.50		23.53 ± 10.12		22.48 ± 11.87		0.004 b

^aTwo-sided χ² test for the frequency distributions of selected variables between low and high exposure level.

^bt-test of the difference between the two exposure groups.