Scientists Dig Hole To The Center Of The Earth, They Hear Voices

A Strange Sound

Ivan heard something completely different from the type of sounds usually recorded from the layers of sediments. It sounded uncannily similar to a human sigh: he looked around, wondering if perhaps it had been one of the team members. 

But everyone else had raised their sight from their notepads with a puzzled expression. Had they heard the same as him? Perhaps everyone else had the same question on their minds. Still, they all went back to focusing on the task at hand. But right then, Ivan heard something else.