Refrigerator sounds
Clicks and hums as the compressor cycles are normal, as are gentle fan whirs and the occasional crackle of defrost. A loud buzz that never stops, rapid clicking on start attempts, or new rattling from the back are not.
Washer sounds
A healthy washer thumps lightly on spin with heavy loads. Banging that moves the machine, grinding during agitation, or a high whine that climbs with spin speed point to suspension, drive, or bearing wear.
Dryer sounds
A soft thump per revolution can be a flat spot on a roller, and it gets worse. Squealing that starts with the load is usually rollers, idlers, or a belt asking for attention while the parts are still cheap.
Dishwasher and disposal sounds
Dishwashers hum, swish, and drain loudly by design; grinding or rattling mid-wash means something hard is in the pump or chopper area. A disposal that hums without spinning is jammed: power off, hands out.
The rule for every appliance
New is the keyword. Any sound the machine did not make last month deserves attention, because noises are how moving parts announce wear while the repair is still small.