Hearing deficits contribute to or cause speech delay in children. The incidence of profound-to-severe hearing loss is estimated to be 1 in 1,000 live births, and twice that in infancy and childhood. Hearing loss or deficits may be classified as conductive, due to dysfunction of the external or middle ear, or sensorineural, due to a malfunction of the cochlea or auditory nerve. Most sensorineural hearing loss appears to be present at birth and is, therefore, termed congenital.

Hearing loss can have numerous etiologies. Most inherited hearing loss is autosomal recessive and the child’s sole disability. There are also many genetic disorders associated with hearing loss, including Treacher Collins syndrome (deformed auricles), Waardenburg syndrome (white forelock, irises of different colors), CHARGE association (eye, gastrointestinal, and other malformations), Down Syndrome (small auricles, frequent otitis media), trisomy 13 and trisomy 18 (central nervous system malformations), Usher syndrome (retinitis pigmentosa, central nervous system effects, loss of smell, associated psychosis), and cleft palate. Nongenetic causes of hearing loss include prenatal and postnatal infections, exposure to ototoxic agents (e.g., aminoglycosides), anoxia, prematurity, and trauma.

Universal hearing screening is recommended before postpartum hospital discharge and for any infant born outside of a hospital. Audiological and medical evaluation of children who failed their screen and 1-month rescreen should be performed to confirm hearing loss before 3 months of age, and intervention must occur before 6 months of age. As infant screening can miss children with mild-to-moderate, progressive, or acquired hearing loss, a hearing assessment should be repeated in any child with a language or speech delay. Published guidelines for receptive and expressive skills exist to help delineate a language delay. After infancy, a rough estimate of a child’s expressive language skills can be used as follows: speech should be 50% intelligible by age 2, 75% intelligible by age 3, and 100% intelligible by age 4. A delay of 25% or greater is considered significant.

Once a child is diagnosed with hearing impairment, management depends on the degree of loss and the preference of families. Amplification devices (e.g., hearing aids, assistive listening devices) are the mainstay of management for moderate-to-profound hearing loss and require a pediatric audiologist for proper prescription and fit. Cochlear implantation should be considered for children with bilateral severe-to-profound sensorineural hearing loss who do not benefit from amplification. Research has shown large, unpredictable individual differences, but significant overall improvement in language development and speech production. The mode of communication (primarily aural-oral vs. manual sign language) is an important decision for the family. Early identification and intervention for hearing loss is crucial, because it enables children to stimulate brain pathways, promote brain maturation, and acquire language skills during critical stages of development.