Residents of Ranchlands in northwest Calgary will get to hear a recording of a nagging humming sound that has caused some people to lose sleep and patience.

Richard Patching, an acoustical engineer working in the area, will play the sound at a meeting on Wednesday, Sept. 29 in the hope that they can pinpoint the source of it.

Reports of the sound were first made about 18 months ago. Patching describes it as a low frequency, low-level humming, like rumble of an air conditioning unit. He says it could be caused by any number of things.

"We're looking at possible air conditioning units, we're looking at the Calgary water system because one of the main watermains for that area goes up fairly close through this area," he said.

Patching said it's also possible the noise is related to electrical generators or substations, cell phone towers or traffic.

"We have found some features that are fairly common at a couple of spots," he said. "We're looking at possibly motor sounds … like big industrial motors, and it also could be that whatever the source is, the houses shake at those frequencies as well, so it sort of amplifies it and that could be part of it."

Patching warns that, even if the source of the sound can be detected, it might not be possible to stop it.

"For example, I mean, should it turn out to be air conditioning units, how many buildings in this area have air conditioning units?" he said.

"There are things that are possible with limited effort but if it's every air conditioning unit in the west side of town is a problem, maybe we can't do something about it."