aftersound vs thud

aftersound

• A sound that persists or remains audible after its source has ceased to produce it; the perception of such a sound. 

• The second, slower phase of decay in the sound made by a piano string when it is struck. 

thud

• The sound of a dull impact. 

• A slower, dull impact with a wide surface area. 

• A hard, dull impact. 

• To make the sound of a dull impact.