I have really good hearing . but lately my left ear has been "clogging " and that normally doesn't happen as often as it has lately. what could it be?

Many possibilities: Needs an examination. May simply be accumulation of wax which once removed will solve the problem but also may be other issues such as diseases of the ear canal (otitis externa) or middle ear (otitis media or effusion). An assessment by a doctor licensed in the area will be useful here to examine the ear and work out the likely diagnosis and treatment. All the best

Maybe: fluid behind your ear drum or wax clogging your eustacian tube?