Noise level due to ventilation

Since a few days, I am back to my previous laboratory to collect some more samples. While looking after my rats, I measured the noise level with a dBmeter. The conditions are:

  • 8.30 am
  • doors are left open (except in the housing unit) as it is usually the case
  • five samples per room: one in each corner of the room (without moving any furniture) and one in the middle
  • measures taken at ear height
  • device: YF-20 (YFE)

noise level measures

The general mean is 61.7+/-3.3dB. But if we go into the details, a Kruskall-Wallis ANOVA shows most of the rooms have the same dB levels. But there is a significant statistical difference between the room where we perform experiments and the housing unit (p < 0.05). And there is a very significant statistical difference between the experiments room and the second office (p < 0.005). A significant statistical difference is also there between the two offices (p < 0.05; now guess in which one I am …).

Although very high compared to other labs, these levels are not considered as harmfull (same level as a busy restaurant – but you don’t stay 8hours a day in a restaurant). And anyway I am alway wearing ear plugs (3M 1100). On their box, it’s written they reduce noise level by 20-30dB.