text: what could cause profound hearing loss in one ear only for a small child, other than injury?   a couple of answers to that question:  depending on how small the child is, the profound hearing loss may have been there from the time the child was born, but was only noticed as a consequence of a workup for something else (eg, an injury).  but, assuming the hearing loss is new in onset, the question becomes a bit more difficult to answer:  there are two types of hearing loss, one which is the result of a loss of the nerve and hearing organs, and one which is the result of fluid buildup in the middle ear space or a rupture of the tympanic membrane  it is rare for fluid or tm rupture to cause "profound" hearing loss (if you use the official definition of "profound"), but it can definitely cause a significant amount of deafness.  neural hearing loss can be caused by injury.  it can also be caused by viral infections, though this is more common in adults.  and it can be congenital but late-manifesting.