Midrash for Chagigah 5:9

והאי באזניהם מבעי ליה באזניהם דכולהו ישראל ההוא מנגד כל ישראל נפקא אי מנגד כל ישראל הוה אמינא אע"ג דלא שמעי כתב רחמנא באזניהם והוא דשמעי

But "in their ears" is needed [for a different proof] - in the ears of all Israel This this comes out of the words "before all Israel." If it were [learned out only] from "before all Israel", I would say even they could not all hear, the Merciful One wrote "in their ears", they must have heard.

Sifrei Devarim