Programs that pay for or provide access to TTY equipment (also known as text telephones, TDDs and telecommunication devices for the deaf), or other specialized telecommunications devices such as voice carry-over telephones, amplified telephones, telebraillers, voice-activated telephones, sip-n-puff telephones or large visual displays for use at home or in the office by people who are deaf or hearing impaired, have speech disabilities or physical limitations, or need to communicate with a person with a hearing impairment or speech disability. Included are programs that pay for or loan such equipment to people with disabilities or organizations serving them, or which operate sites where such equipment is available for use by the public.

Programs that identify infants, toddlers and in some cases, preschoolers who show evidence of or are at risk for lags in physical development, cognitive development, language and speech development, psychosocial development or self-help skills, and provide or coordinate the delivery of an enrichment program in order to minimize the potential for a developmental delay and to meet their current developmental needs. The program may include early identification activities (child find); a developmental evaluation; a review of family concerns, priorities and resources; meetings with the family to develop an individualized family service plan; service coordination to ensure that the individual and his or her family receive needed services which may include but are not limited to physical therapy, occupational therapy, audiology, health/medical services, nursing services, nutrition services, psychological services including specialized play groups or therapy sessions, counseling, speech and language assistance, special instructional services, transportation, and parenting skills development; and ongoing evaluation of the child's progress and his or her changing enrichment needs. Included are "birth to three" programs and federal, state or local programs that address the needs of slightly older children or children not otherwise eligible for "birth to three" programs.

A disruption in the normal hearing process that may occur in the outer, middle, or inner ear, which prevents sound waves from being converted to electrical signals and nerve impulses from being transmitted to the brain to be interpreted. Included are conductive hearing loss that results from abnormalities of the external ear and/or the ossicles of the middle ear; sensorineural hearing loss that results from malfunction of inner ear structures (i.e., cochlea); and central auditory dysfunction that results from damage or dysfunction at the level of the eighth cranial nerve, auditory brain stem, or cerebral cortex. Hearing loss may be present at birth (congenital) or become evident later in life (acquired); and may or may not preclude the normal development of language. The severity of hearing loss is measured in decibles (dB). The threshold or 0 dB mark for each frequency refers to the level at which typical young adults perceive a tone burst 50% of the time. Hearing is considered normal if an individual's thresholds are within 15 dB of normal thresholds. Severity of hearing loss is graded as mild (26-40 dB), moderate (41-55 dB), moderately severe (56-70 dB), severe (71-90 dB) and profound (90 dB).

Partial or complete hearing loss, generally in the severe to profound range, that is present at birth or occurs later in life. Functionally, individuals who are termed "deaf" are unable to hear well enough to rely on their hearing and use it as a means of processing information.