noun / adjective
ticking
TIK-ing/ˈtɪkɪŋ/
A sequence of brief mechanical clicks.
He holds a small clock beside his ear, listening to its ticking.

Etymology
Ticking is formed from tick, the imitative clicking word, with -ing. It is unrelated to ticking, the mattress fabric.
In context
listen to this pulse which could be the ticking of a clock listen for long enough and you'll find yourself organizing this ticking into groups of two or four
More examples
- The steady ticking of the kitchen timer fills the quiet room.
- She moves the ticking clock away from her bed.
- A faint ticking comes from inside the machine.
Forms
ticking
tick verb — To make repeated short clicking sounds.