What does “to shout over” mean, particularly as it has been used in a particular passage I’ve read with curious sytnax?

Question

I don’t un­der­stand the mean­ing of shout over as it has been used in the fol­low­ing pas­sage from Pa­tri­cia High­smith’s novel, The Ta­lented Mr. Ri­p­ley:

A well-dressed Ital­ian greeted Dickie warmly and sat down at the ta­ble with them. Tom lis­tened to their con­ver­sa­tion in Ital­ian, un­der­stand­ing a word here and there.

“Want to go to Rome?” Dickie asked him sud­denly.

“Sure,” Tom said. “Now?”

The Ital­ian had a long, gray car with a loud ra­dio that he and Dickie seemed happy to shout over. They reached Rome in about two hours and the Ital­ian dropped them in the mid­dle of a street and said a quick good­bye.

Could some­one please ex­plain to me what to shout over means as it’s be­ing used here?

Answer 1

It literally means to shout in order to be heard over. The radio is loud, but they're are perfectly happy to shout over the radio (presumably because the rest of the car is worth it).