According to the Mayo Clinic, causes of hearing loss in one ear include infections, a ruptured eardrum and a build-up of earwax. Factors for general hearing loss in one or both of the ears include occupational noises, aging, recreational noises, certain illnesses and some medications.
Overexposure to loud noises leads to damage to the hairs and nerve cells in the cochlea, which transmits sound signals to the brain, notes the Mayo Clinic. Over time, the damage can impede the transmission of electrical signals to the brain, resulting in hearing loss. A loss of hearing can also muffle high pitched noises.
As earwax starts to build up in the ear canal, it lowers the conduction of sound waves. If earwax build-up occurs, it can be resolved with earwax removal. The Mayo Clinic also notes that tumors, abnormal bone growths and ear infections in the outer or middle ear can cause a loss in hearing. Sticking a foreign object in the ear can rupture the eardrum and lead to a loss of hearing in one ear, as can sudden shifts in pressure and bursts of loud noises.
A visit to the doctor is recommended for individuals who have to turn music, the radio or the TV up more than usual and for those who have difficulty hearing another person when there is background noise.