We can draw several conclusions from this data:

1. The running of the A/C units causes a steady level of noise at about 59 to 60 dBA (red arrow).

2. From midnight to 5 am the A/C was not running. The true background noise level could be

measured during these hours, and it is about 39 to 40 dBA (green arrow).

3. Other noises due to the actual use of the room by office personnel can be as high as 86 to

88 dBA and are typically 65 to 78 dBA. One can also see the noise effects of the retirement

party and ceremony (from 5PM till about 9PM or 10PM on the 13th).