IDENTIFYING PERCUSSION SOUNDS
Percussion produces sounds that vary according to the tissue being percussed. This chart lists important percussion sounds along with their characteristics and typical sources.
SOUND INTENSITY PITCH DURATION QUALITY SOURCE

Resonance Moderate to loud Low Long Hollow Normal lung
Tympany Loud High Moderate Drumlike Gastric air bubble, intestinal air
Dullness Soft to moderate High Moderate Thudlike Liver, full bladder, pregnant uterus
Hyperresonance Very loud Very low Long Booming Hyperinflated lung (as in emphysema)
Flatness Soft High Short Flat Muscle