Ernie Werezak can't explain the noises he recorded from the balcony of his Fairmont Drive apartment in Saskatoon on Saturday morning.

"I have never heard anything like this in my life yet," he said.

Werezak said he was woken up around 5 a.m. by a loud sound. He grabbed his camera, shot a video and put it on YouTube.

"It was a loud noise coming probably from northeast Saskatoon. It seemed like it was in the air.”

Werezak's video isn't the only one on YouTube featuring strange sounds in Saskatoon – there are several. Last winter, similar sounds were also recorded in North Battleford. 

Jean-Pierre St. Maurice, a physics professor at the University of Saskatchewan, says under certain temperature conditions sound waves generated from the ground can do unexpected things.

"Under the right atmospheric conditions, you can have sound come back toward the ground to propagate along the ground over long distances not too far from where the sound has been emitted," St. Maurice said. "And to make things interesting, in the process the sound will also get distorted if the distances get large."

Several people have offered possible sources for the sound to Werezak but he doesn't believe the sound he heard was created by something common, such as a snow grader. Werezak says he'll continue to search for answers, and keep his ears to the sky.