Some people lose their hearing slowly as they age. This condition is known as presbycusis (prez-buh-KYOO-sis). Doctors do not know why presbycusis happens, but it seems to run in families.

Another reason for hearing loss may be exposure to too much loud noise. This condition is known as noise-induced hearing loss. Many construction workers, farmers, musicians, airport workers, tree cutters, and people in the armed forces have hearing problems because of too much exposure to loud noise. Sometimes loud noise can cause a ringing, hissing, or roaring sound in the ears, called tinnitus (tin-NY-tus).

Hearing loss can also be caused by a virus or bacteria, heart conditions or stroke, head injuries, tumors, and certain medicines. 

There are also some surprising medical causes of hearing loss such as diabetes or hypertension. 

Hearing loss can also be hereditary and there are multiple forms of genetic hearing loss. 

Source: Hearing Health Foundation  http://hearinghealthfoundation.org