Guardian: On holiday recently, I visited the Japanese sacred area of Kumano Kodo. Miles of treks mark pilgrim routes from the ancient capital of Kyoto to a number of shrines located around the Wakayama peninsula.
We were walking on a high ridge and stopped to look and to listen to the forest sounds bird song, a variety of insect noises and large butterflies.
But something was strange. The sound was coming at us in mono not in stereo. One side of the ridge fell off steeply. The forest was lush, varied...