
Talk one's ears off
Talk one's head off / Speak freely / Talk in full flow / Talk non-stop / Be a motormouth (Slang) / Be a ratchet mouth

Parlare a ruota libera 
Talk one's head off / Speak freely / Talk in full flow / Talk non-stop / Be a motormouth (Slang) / Be a ratchet mouth

Parlare a ruota libera 
Meanings
Fig.: to speak endlessly, with or without a preset outline
Examples
Sometimes spending time with Lisa can be very hard. She talks non-stop and she could talk your ears off
A volte passare del tempo con Lisa può essere molto difficile,
soprattutto quando comincia a parlare a ruota libera, non si ferma mai
fino a sfinirti
Having a cup of coffee with grandma Lucy is always nice, unless she starts talking about her grandchildren. That's the moment you've got to leave, otherwise she will talk your ears off
Bere un caffè con nonna Lucia è un piacere, ma se comincia a parlarti dei nipoti, quello è il momento di andarsene, perché parlerà a ruota libera e incessantemente fino a rincretinirtiOrigin
This phrase alludes to a person talking so much that they abuse the other person's ear to the point that it falls off