expression, noun
inner voice; voice of one's heart; what one really thinks
Refers to one's true thoughts or feelings, often contrasted with spoken words. Common in self-reflection or when someone's real opinion is revealed.
彼の言葉とは裏腹に、心の声は違っていた。
Contrary to his words, his inner voice was different.
心の声に従って進路を決めた。
I decided my career path by following my inner voice.