The clicking sound you hear could be one or both of the valves of your eustachian tube struggling to open and shut, or a bubble trapped in the inner ear, possibly by earwax. Get it checked out to make sure it's not a blockage or infection, but don't go crazy trying everything an ENT might recommend. I'd take clicking and a bit of discomfort at times rather than the problems I have after an ENT over prescribed treatment for what was post nasal drip and clicking that went away after chewing gum, yawning deeply and waggling my jaw around as you would if you were on an airplane and the pressure made them stop up. Good luck to you, I hope you find answers.