Sound strata – which do you hear?

Sitting under the tree just now, various sound strata were moving in and out of focus.  I sat for ages until I noticed the frogs.  There must be hundreds of them – producing the richest and fullest of elements of the sound spectrum.  But I didn’t hear them at first, and for a while I lost them and wondered if they’d stopped.  But it was only a focus issue.  Once they were back, they were back to stay. Continue reading