Rimbalzi comes from the verb rimbalzare, meaning 'to bounce' or 'to rebound'. It's an active and dynamic word that isn't as common in everyday romantic song lyrics.
In the context of the song, the singer uses it to describe how the memory or presence of the loved one 'bounces' or 'rebounds' within his senses. It vividly conveys the idea that this person's impact is constantly present and recurring, making it a compelling choice.
Biagio Antonacci's "Quanto tempo e ancora" opens at a party, running into someone he didn't expect to see: "Tra tanti amici, non ti aspettavo qui" (Among so many friends, I didn't expect you here). The old feeling comes rushing back — "E ti accompagnava un'emozione forte" (And a strong emotion came with you) — and the chorus becomes the whole song's question, repeated three times over: "Ma quanto tempo e ancora, ti fai sentire dentro" (How much longer, and still, will you make yourself felt inside me), "Quanto tempo e ancora, ti metti proprio al centro" (How much longer, and still, do you put yourself right at the center). He isn't over her, and the song never pretends otherwise.
By the second verse he's chosen distance instead: "Sì, forse è meglio, così non mi vedrai" (Yes, maybe it's better, that way you won't see me), followed by "Piangere poi ridere, poi, prenderti un po' in giro" (Crying, then laughing, then teasing you a little) and "Fingere davanti a tutti, di aver dimenticato" (Pretending in front of everyone that I've forgotten). The title's own question — how much longer — never actually gets answered.