Cavalier King Charles Hearing

Hi all im new to this forum/site. I joined ot get advice on my beloved Cavalier King Charles as he seems to be somewhat ignorant well thats what i thoguht.

About 2 years ago he developed a bad ear infection and has regular visits to the vets for anti biotics, his other ear is fine.

Hes only 4 years old next month, and ive noticed when i call him or people knock on the door he never responds anymore and i am now wondering if Charlie is now actually deaf.

this seems to have happened over a short space of time, and i am very worried.

Any one else have simlar problems/advie they can give me?