vocalization, interpreter, representative, part, spokesperson, sound, articulation, quavering, vocal, raspy, more...

silence, muteness, quiet, hush, speechlessness

soprano, alto, tenor, bass, baritone, mezzo-soprano, countertenor, contralto, more...

low, loud, own, deep, soft, human, clear, sweet, quiet, inner, familiar

speak one's piece,   speak one's mind,   speak freely,   to speak up,   to have a say,   author's asset,   raise concerns,   say with concern,   share one's view,   share opinion