I have the same problem right now, and once my ear pops, I can hear everything again, but, the other one fills up. It is sinus caused from the pollen that is out right now. It happens to me every year. The dr. has put me on Allegra-D. My daughter takes zyrtec. This is helping so much. My brother also has this same problem, and he can finally hear again, after taking zyrtec. Hope this helps :)