An elderly person has a habit of doing gheebat and it is very difficult for me to stop him and I also do not…

Answer

To listen to someone who is backbiting is not Haram in it self, however the listener must act in accordance to enjoining the good (Amr bil Marouf) and forbidding the evil (Nahy anil Munkar)., and if it is not effective one must show their dissatisfaction from the person performing the backbiting.