Table 2. Overnight MICU A-weighted and C-weighted Sound Levels.
| Mean Leq (SD) | Mean (SD) of Maxima | Mean (SD) of Minima | LAF90 | ||||
|---|---|---|---|---|---|---|---|
| Time Period | dBA | dBC | dBA | dBC | dBA | dBC | dBA |
|
Overnight: 20:00 – 08:00 |
53.5 (4.1) | 63.1 (3.8) | 80.0 (4.2) | 84.9 (5.5) | 46.5 (4.9) | 57.5 (3.6) | 49.5 (4.7) |
|
Beginning of Night: 20:00 – 23:59 |
54.6 (3.9) | 63.7 (3.6) | 77.6 (4.2) | 82.3 (5.8) | 47.9 (4.5) | 58.9 (3.3) | 50.5 (4.6) |
|
Middle of Night: 24:00 – 3:59 |
52.7 (4.5) | 62.6 (4.0) | 74.1 (4.5) | 79.0 (5.5) | 47.2 (5.0) | 57.9 (3.9) | 49.5 (4.9) |
|
End of Night: 04:00 – 08:00 |
53.2 (4.5) | 63.1 (4.0) | 76.1 (5.5) | 81.6 (5.8) | 47.9 (4.9) | 58.6 (3.3) | 49.8 (5.1) |
dBA n=53
dBC n=46
Difference of mean Leq for (dBA) and for (dBC) had p-value < 0.0001 (t-test) for all pairs.
Difference of means of minimal for (dBA) and for (dBC) had p-value < 0.0001 (t-test) for all pairs.
Abbreviations: dBA, A-weighted decibel unit; dBC, C-weighted decibel unit; LAF90, sound level exceeded for 90% of the measurement period; Leq, Sound Level Equivalent; SD, standard deviation