A 45-year-old locomotive driver consulted his family physician because of a ringing sensation in both his ears for the past 5 years.
Away from work, he had difficulty understanding conversations in crowded rooms, and he said he often argued with his wife about the volume of the television set.
He also complaints of depression that began soon after the onset of the tinnitus. He was otherwise normal and is not having any other significant medical history.
On examination, his physical findings were normal.
An office audiogram was performed (see the image). What is the most probable diagnosis?