Sibilance
The repetition of soft, hissing consonant sounds such as s, sh, and z.
Sibilance is a specialized kind of consonance built on hushing, whispering sounds. Writers use it to suggest quiet, secrecy, menace, or the slither of movement, letting the sound act out the meaning. Overused, it can feel oppressive, which some poets exploit deliberately.
Example
The poem’s rushing “s” sounds mimic the sweep of the wind Shelley invokes, making the breeze audible in the lines.
Ode to the West Wind · Percy Bysshe Shelley