any blunt injury to your ear will cause one of the following problems which can cause hearing loss 1. rupture of ear drum which may fail to heal 2. injury to sound conducting bones 3. injury to inner ear causing sensory neural hearing loss first two causes can be treated by surgery but sensory neural loss will require hearing aids you need to undergo ear examination by an ENT and audiological examination such as audiogram and tympanogram. once cause of your hearing loss is confirmed then it can be treated accordingly I assure you it won't progress to your other ear