voicelessness vs powerlessness

voicelessness and powerlessness both are nouns.

Word	Noun	Adjective	Verb	Adverb
voicelessness	Yes	No	No	No
powerlessness	Yes	No	No	No

As nouns, powerlessness is a hypernym of voicelessness; that is, powerlessness is a word with a broader meaning than voicelessness:

voicelessness: having no voice in the management or control of affairs
powerlessness: the quality of lacking strength or power; being weak and feeble

Other hypernyms of voicelessness include impotence, impotency.

voicelessness (noun)	powerlessness (noun)
having no voice in the management or control of affairs	the quality of lacking strength or power; being weak and feeble
speaking softly without vibration of the vocal cords
(phonetics, of a consonant) The property of being spoken without vibration of the vocal cords, as [t], [s], or [f].
a disorder of the vocal organs that results in the loss of voice