During a recent trip to BG me and my two friends i was with decided to each sit on a stone for about 5 minutes in silence to see if we could hear anything. My one friend was sitting on the checkered stone and to the left he heard footsteps, he said he heard two footsteps, then it would stop, and he would hear two more. We walked around a bit more and decided to sit down again, this time i sat on the checkered stone. After about 2 minutes i heard the footsteps as well.