Musannaf Ibn Abi Shayba 18:113

Abu Bakr narrated to us, he said: Muhammad ibn Bakr narrated to us, from Ibn Jurayj, from Ibn Tawus, from his father, who said: Abu Bakr said: The ear is five-fifteenths [in blood money] because it does not impair hearing, and it is covered by hair and the turban.