cry, whimper, neigh
啾 centers on high-pitched, plaintive vocal sounds: crying, whimpering, or neighing. The common thread is a thin, drawn-out call expressing distress or animal noise.
啾 combines 口 (mouth) with 秋, which likely contributes the sound and suggests a thin, high sound like an autumn breeze or insect cry.
The mouth 口 on the left and autumn 秋 on the right suggest a thin, sad cry like the sound of wind through dry autumn leaves. Picture a small mouth whimpering in the chilly autumn air.
For シュウ, imagine a shoe squeaking out a high-pitched whimper: shoe -> シュウ, and the sound is like a thin cry.
spine-chilling (like the wailing and weeping of a restless ghost); hair-raising