What is a siblance?

Answer 1

"Essy", exaggerated "s" or "sh" sounds in vocals. Sibilant sounds carry most of their energy through the 4Khz to 8Khz range, but can extend to 10kHz, depending on the individual. Sibilance is often heard on radio.

Answer 2

Sibilance is a literary device where there is repetition of "s" and "sh" sounds in words close to each other. It is often used to create a hissing or rushing sound effect in writing.