piano hums after keys released

[slane]

I've noticed for awhile now,that after I release the keys on my piano the piano continues to hum.
The tuner/technician says that's normal but I can't help thinking the dampers aren't hard enough against the strings.

So do pianos hum when the keys are all released? Or do I need someone else to look at it?

[outin]

Yes, mine does and there definitely is nothing wrong with the dampers, in fact they are too eager...

[pristinepiano]

Sometimes dampers are timed to properly dampen and fit the strings correctly with enough force, but the damper heads dont have enough mass to do the job as efficiently as possible. Generally seen in lesser quality spinets and sometimes around the tenor break in grands.  If the hum is more higher pitched, like above E5-C6...those notes are typically not dampened at all and will continue to ring from sympathetic vibration....this is normal.