You will hear this sound at the apex in the left lateral position. Use the bell of the stethoscope. Normal in children and young adults. It is abnormal when it persists in a person. Usually abnormal in adults over the age of 40 and can be an early sign of heart disease or congested heart failure.
verb (used without object), subsided, subsiding. 1. to sink to a low or lower level. 2. to become quiet, less active, or less violent; abate: The laughter subsided. 3. to sink or fall to the bottom; settle; precipitate: to cause coffee grounds to subside. Origin of subside.
The central area of subsidence usually is subjected to a gradual lowering, possibly suffering some tilt and strain as the workings pass beneath. This may cause damage to such items as roads and pipelines but this is easily repaired and there is little evidence of it being a subsidence area after movement ceases.