whisper, murmur
囁 centers on soft, low-volume speech: whispering or murmuring, often in a way that is not meant to be heard clearly by others.
囁 combines 口 (mouth) with 聶, which is composed of three 耳 (ear) elements. The structure suggests a mouth speaking into many ears, fitting the idea of whispering or murmuring. The exact historical development is uncertain, but the component arrangement is visually suggestive.
A mouth 口 beside three ears 聶: imagine someone leaning close to whisper, their words reaching only the ears right next to them.
For ショウ, picture a quiet show where the audience must whisper: show -> ショウ, and the mouth 口 speaks softly so only nearby ears 聶 can hear.