A MOREDIKE vort I saw today. Chazal say that at Har Sinai the Jews SAW the קולות [sounds]. How do you see sounds? It was a supernatural experience [and I'm a guy who likes to eat super natural food so I can appreciate it].
In Kedusha [nusach sefard] we say that when the geula comes [as opposed to recently when I came to the Geula. The place, that is..:)] הוא ישמיענו ברחמיו שנית לעיני כל חי - He will have us hear to the EYES of all the living. There we have it again. Seeing what is heard.
Or a pasuk ונגלה כבוד השם וראו כל בשר יחדיו כי פי השם דיבר - The glory of G-d will be revealed and everyone will SEE that Hashem spoke!
Something else!