Translation of "Mouthpiece" in Japanese

To be his mouthpiece; to change our society;

息子のスポークスマンになる為 社会を変える為

We've got the mouthpiece -- that's the vocal folds --

マウスピースが声帯ヒダにあたり

She covered the mouthpiece of the phone with her hand.

彼女は電話の送話口を手でおおった。