I inexplicably heard a pop and lost hearing in one of my ears. there is a terrible ringing noise. what caused this? will this pass?

See ENT: You need to see an ENT doctor to find out what may have occurred. Sounds like you have developed tinnitus--ringing in one ear. The ENT doctor may want you to see a neurootologist and to have a CT of your head.

Seek a formal eval: This is somewhat concerning and means you require an evaluation of your ear, and sooner rather than later. Sudden loss shouldn't go unattended! Good luck.