Table 3.
Comparison of Noise Levels between Two Ward Groups.
| Variable | CW Group (n = 101) | AOW Group (n = 91) | t/χ2 | P |
|---|---|---|---|---|
| Noise levels (dB LAeq) | ||||
| 8 h night | 47.36 ± 6.78 | 45.12 ± 6.56 | 2.325 | 0.021 |
| 16 h day | 57.91 ± 6.63 | 55.16 ± 6.54 | 2.881 | 0.004 |
| 24 h | 55.92 ± 7.94 | 53.35 ± 7.33 | 2.319 | 0.021 |
| No. of noise events >70 dB LAmax (events) | ||||
| Day (16 h period) | 524.92 ± 89.19 | 489.37 ± 69.78 | 3.091 | 0.002 |
| Night (8 h period) | 37.98 ± 10.26 | 35.35 ± 6.86 | 2.105 | 0.037 |
| Maximum sound level (dB) | 86.15 ± 9.27 | 82.36 ± 8.16 | 2.993 | 0.003 |
| Frequency spectrum | 6.172 | 0.046 | ||
| Low-frequency noise | 36 (35.64%) | 39 (42.86%) | ||
| Mid-frequency noise | 48 (47.52%) | 47 (51.65%) | ||
| High-frequency noise | 17 (16.83%) | 5 (5.49%) | ||
| Statistical sound level L50 | 48.72 ± 6.31 | 47.36 ± 7.07 | 1.411 | 0.160 |
AOW = acoustically optimized ward, CW = conventional ward