Tap the drainpipe; a blockage will create a muffled sound.

Then in my twilight world of darkness and muffled sound, the water began to trickle, then splash, into my nose and gasping mouth.

I can remember the muffled sound of the music coming through the floorboards.

No more fuzzy programmes with muffled sound and colours like confetti in a puddle.

The muffled sound, dropouts, sudden changes in sound quality, unsteady pitch and other defects heard all too often are almost always accumulated tape copy defects.