I only have a few logged dives since I've returned to diving. However, I did experience this once. I was diving at Blue Grotto. When I came out of the water, I experienced the "muffled" hearing and felt like I had water in my ear. I don't know if it was just a coincidence but, it was my deepest dive to date (around 91 feet).
For me, it was very disconcerting because, I had an ear infection about 6 years ago which resulted in me being completely deaf in my right ear. So, when I came out of the water and my hearing in my left ear was muffled to the point of not being able to understand any conversation, it scared the crap out of me. Fortunately, it cleared up within a few minutes.
Contrary to popular believe, ear infections don't ALWAYS come with pain. When I had the ear infection that resulted in hearing loss, it happened over night and there was absolutely no pain. There was apparently enough swelling in my inner ear that it cut off blood flow to my auditory nerve but, not enough to cause any pain. The rest is history. Lesson learned is to always take situations with your hearing seriously and seek medical attention if it doesn't clear up in a very short period of time after diving.
Many folks are prone to swimmer's ear, especially when diving in lakes, quarries, and springs where there frequently isn't a free flow of water (i.e. where bacteria can concentrate). And, others will get swimmer's ear even when diving in environments where bacteria doesn't tend to concentrate (i.e. open ocean).
Since I was introduced to ear beer, I always keep a bottle with me and, as a minimum use it at the end of every diving day, regardless of where I'm diving. I can't risk getting another ear infection in my one good ear.