This strange sound has been recordered on April 4, 2012, in Świniarc, Poland.
It’s 2:06 – 2:15 am. The sound has low volume but hearing it live was a great experience. Finally I have found that these sounds are real! Deep voice, like someone blowing a trumpet. It was definetely not a plane or something you hear every day. A beautiful sound. I wish everyone might hear it 🙂 Louder periods: 0:04, 0:28, 0:49, 1:03, 1:16, 1:35, 1:59, 3:04.