IPA: //sʌbˈvoʊkəli//
KK: /sʌbˈvoʊkəli/
In a way that involves speaking or producing sounds quietly, often without vocalizing them fully.
She practiced her speech subvocally to avoid disturbing others.
Subvocally → It is formed from "sub-" (meaning under or below) and "vocare" (meaning to call or voice). The word "subvocally" refers to speaking or voicing something in a manner that is not fully audible, as if under the level of normal speech.
Think of speaking 'under' ('sub-') your breath or voice ('vocare') — that's why subvocally means to speak quietly or softly.