Table 3.
Cases of hypertension and associated exposure to different noise frequencies
| Characteristics | Case group (n = 46) | Control group (n = 774) | Total subjects (n = 820) | P -value |
|---|---|---|---|---|
| LAeq 8 h (dBA) |
|
|
|
|
| Median (Q1, Q3) |
81 (79, 82) |
79 (77, 82) |
79 (77, 82) |
0.016a |
| Frequency components |
|
|
|
|
| 31.5 Hz (dB) |
|
|
|
|
| Median (Q1, Q3) |
29 (26, 31) |
27 (25, 30) |
27 (25, 30) |
0.222a |
| 63 Hz (dB) |
|
|
|
|
| Median (Q1, Q3) |
43 (41, 45) |
41 (38, 44) |
41 (38, 44) |
0.026a |
| 125 Hz (dB) |
|
|
|
|
| Median (Q1, Q3) |
50 (48, 52) |
49 (47, 51) |
49 (47, 51) |
0.032a |
| 250 Hz (dB) |
|
|
|
|
| Median (Q1, Q3) |
55 (53, 56) |
54 (52, 55) |
54 (53, 55) |
0.017a |
| 500 Hz (dB) |
|
|
|
|
| Median (Q1, Q3) |
58 (57, 60) |
58 (56, 59) |
58 (56, 59) |
0.032a |
| 1000 Hz (dB) |
|
|
|
|
| Median (Q1, Q3) |
61 (60, 63) |
61 (59, 63) |
61 (59, 63) |
0.070a |
| 2000 Hz (dB) |
|
|
|
|
| Median (Q1, Q3) |
59 (57, 61) |
59 (57, 61) |
59 (57, 61) |
0.120a |
| 4000 Hz (dB) |
|
|
|
|
| Median (Q1, Q3) |
57 (54, 58) |
56 (53, 59) |
56 (53, 59) |
0.458a |
| 8000 Hz (dB) |
|
|
|
|
| Median (Q1, Q3) | 50 (48, 52) | 49 (45, 52) | 49 (45, 52) | 0.096a |
dB = decibel; dBA = A-weighted decibel; LAeq 8 h = A-weighted equivalent sound level at 09:00–17:00; Q1 = first quartile; Q3 = third quartile. aWilcoxon signed rank sum test of the difference between the two groups.