Hearing Loss Testing Act of 1991 - Directs the Secretary of Health and Human Services to: (1) require that every child born in the United States be tested for hearing loss at the time of birth; and (2) establish uniform standards for such testing. Requires each health insurance policy, including contracts for coverage by health maintenance organizations, which provides for any benefits with respect to a newborn to include coverage for newborn hearing loss testing.

Amends title XIX (Medicaid) of the Social Security Act to add newborn hearing loss testing to the definition of screening services.

Directs the Secretary to provide for such a grant or other program as necessary to assure that all newborns in the United States are tested for hearing loss at the time of birth. Authorizes appropriations.