Yellowknife (Oct 31/03) - Rattling windows and a disrupted sleep left one Kam Lake resident wondering what all the racket was about.

Excessive noise from aircraft early Oct. 15 might now be the explanation, according to Michel LeFrance, Yellowknife airport manager.

Andrew Geggie described the loud noise as thundering, ceasing for a short time, then resuming its loud roar.

That morning, at 2:54 a.m. and 3:17 a.m. two Air Tindi medevacs arrived at the airport from Fort Providence, LeFrance said.

"It could be from ducting which traps sound," LeFrance said.

Because of this phenomenon, he said it is quite possible both aircraft sounded louder due to the deflecting of sound between the ground and a low cloud base.

LeFrance said the combination of almost overcast conditions and dense, colder air, along with wind conditions, causes such an effect.

And while Yellowknifers become quite tolerant of the high traffic flow across the city, he said any noise out of the ordinary becomes more noticeable.

"They would have seemed much louder as a result."