Slapping over the ear with open hands usually leads to traumatic perforation of tympanic membrane(ear drum), which causes symptoms like diminished hearing, blocked sensation or ringing sensation in the ear. You have to consult a ENT specialist
and get your ears checked. If there is a perforation found in your eardrum
, it usually takes 6 weeks to heal or close completely and also it depends on how well you follow the treatment and instructions given by your doctor. Take care and wish you good health.