I Did The Valslava Maneuver To Unclog My Ears And

I did the Valslava maneuver to unclog my ears and my left ear did the pop and then it was a bit clogged. Later it got a little better but I still have a subtle dull hearing. I can do the valsalvamaneuver but it doesn't make any change. Why do I have dulled hearing in my left ear? Could it be permanent?