Bat Noise in Far North Queensland
Have you ever stayed in a hotel and been woken by the noise of screeching bats?
That’s exactly what the builders of a new hotel in Cairns were concerned about when planning construction. So they called Renzo Tonin’s Brisbane office, looking for a solution for this unusual acoustic problem.
Renzo Tonin engineers got to work. First, they measured the noise from the local bat population who live in trees close to the site. Being nocturnal, bats chatter and screech at night. The builders were worried that this could be noisy enough to disturb future guests sleeping in the hotel suites.
To tackle their noise concern, our engineers started by recording noise levels at the site over a period of seven days. They then analysed this noise data using XL2 Data Explorer software to pinpoint each “bat noise event” from the previous week. A bat noise event can be described as a series of high pitched screeching that lasts for several seconds.
The data showed that the bats are most active from midnight to 4am, and that noise levels reached up to 77dB(A) immediately outside the proposed hotel. The dominant sound energy was in the high frequency range (between 3.15kHZ to 5kHZ).
Our engineers advised the builders on steps they could take to reduce the amount of noise that would reach inside the hotel rooms, and to make sure noise levels stay within the stringent standards set in the Association of Australian Acoustical Consultants (AAAC) guidelines. The best solution was for the hotel to install specifically selected double glazing units in the hotel suites that are closest to the trees where the bats live.
Check back here for an update – we’ll write again once construction is completed.