ascertain (the depth of water in the sea, a lake, or a river), typically by means of a line or pole or using sound echoes
Mr Pattison was sounding the depth of the water with a pole
examine (a person's bladder or other internal cavity) with a long surgical probe
(especially of a whale) dive down steeply to a great depth
he sounded, arching his back steeply and raising his rubbery flukes in the air
convey a specified impression when heard
he sounded worried