Final answer:
The most common autologous site for securing a graft for tympanoplasty is the tragus.
Step-by-step explanation:
The most common autologous site for securing a graft for tympanoplasty is the tragus. The tragus is the small, cartilaginous projection located in front of the ear canal. It provides a good source of cartilage for grafting and is easily accessible in the same surgical field as the tympanic membrane.