A hollow tap

I stepped off the soft cushion and reached the flat surface of the coffee table. The wood felt dense and cool under my footing. Near the edge lay a small ceramic coaster. I paused, watching the still dust motes around it. Slowly, I lifted my arm and tapped the rim with my knuckles. A crisp, ringing vibration hummed into the air and faded. I tried the wooden tabletop next. It gave back a much lower, muffled thud. Two different materials, two distinct notes. I stood still for a moment, listening to the silence settle back down.