Blocked ear, throbbing & can hear heart beat, not too painful. popped once when blowing nose, can't hear well. getting over a mild cold.

Eustachtian tube: This is likely from a blocked eustachtian tube or fluid trapped behind your ear drum. You can try manoeuvres to help open the tube and help drainage. These are called Valsava maneuvers. One is blowing into a blocked straw, another is taking a big breath and holding it and swallowing. Sometimes chewing gum works. If these maneuvers fail to work, see your doctor for medication. All the best.