( See also Hearing Loss Hearing Loss Worldwide, about half a billion people (almost 8% of the world's population) have hearing loss ( 1). More than 10% of people in the US have some degree of hearing loss that compromises their... read more 
.)
In the US, permanent childhood hearing loss is detected in 1.1/1000 infants screened. On average, 1.9% of children reported “hearing trouble.” Hearing impairment is slightly more common among boys than girls; the average male:female ratio is 1.24:1.
Etiology of Hearing Impairment in Children
Neonates
The most common causes of hearing loss in neonates are
Congenital cytomegalovirus Congenital and Perinatal Cytomegalovirus Infection (CMV) Cytomegalovirus infection may be acquired prenatally or perinatally and is the most common congenital viral infection. Signs at birth, if present, are intrauterine growth restriction, prematurity... read more
(CMV) infection (1 Etiology references Common causes of hearing loss are genetic defects in neonates and ear infections and cerumen in children. Many cases are detected by screening, but hearing loss should be suspected if children... read more 
)Genetic defects (see table Some Genetic Causes of Hearing Loss Some Genetic Causes of Hearing Loss
)
Congenital CMV infection is the most common intrauterine infection in the US. CMV infection may account for as much as 21% of all sensorineural hearing loss at birth. In addition, because CMV infection also may cause late-onset hearing loss, CMV may account for as much as 25% of sensorineural hearing loss present at 4 years of age (2 Etiology references Common causes of hearing loss are genetic defects in neonates and ear infections and cerumen in children. Many cases are detected by screening, but hearing loss should be suspected if children... read more ).
Risk factors for hearing loss in neonates include the following:
Low birth weight (eg, < 1.5 kg)
Hypoxemia or seizures resulting from a difficult delivery
Prenatal infection with rubella Congenital Rubella Congenital rubella is a viral infection acquired from the mother during pregnancy. Signs are multiple congenital anomalies that can result in fetal death. Diagnosis is by serology and viral... read more , syphilis Congenital Syphilis Congenital syphilis is a multisystem infection caused by Treponema pallidum and transmitted to the fetus via the placenta. Early signs are characteristic skin lesions, lymphadenopathy... read more
, herpes Neonatal Herpes Simplex Virus (HSV) Infection Neonatal herpes simplex virus infection is usually transmitted during delivery. A typical sign is vesicular eruption, which may be accompanied by or progress to disseminated disease. Diagnosis... read more 
, cytomegalovirus Congenital and Perinatal Cytomegalovirus Infection (CMV) Cytomegalovirus infection may be acquired prenatally or perinatally and is the most common congenital viral infection. Signs at birth, if present, are intrauterine growth restriction, prematurity... read more , or toxoplasmosis Congenital Toxoplasmosis Congenital toxoplasmosis is caused by transplacental acquisition of Toxoplasma gondii. Manifestations, if present, are prematurity, intrauterine growth restriction, jaundice, hepatosplenomegaly... read more 
Craniofacial anomalies Overview of Congenital Craniofacial Abnormalities Congenital craniofacial abnormalities are a group of defects caused by abnormal growth and/or development of the head and facial soft-tissue structures and/or bones. (See also Introduction to... read more , particularly those that involve the external ear Congenital Ear Abnormalities Ears can be absent, deformed, or incompletely developed at birth. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders and Overview of Congenital Craniofacial Abnormalities... read more
Sepsis Neonatal Sepsis Neonatal sepsis is invasive infection, usually bacterial, occurring during the neonatal period. Signs are multiple, nonspecific, and include diminished spontaneous activity, less vigorous sucking... read more or meningitis Neonatal Bacterial Meningitis Neonatal bacterial meningitis is inflammation of the meninges due to bacterial invasion. Signs are those of sepsis, central nervous system irritation (eg, lethargy, seizures, vomiting, irritability... read more
Ventilator dependence
Family history of early hearing loss
Infants and children
The most common causes of hearing loss in infants and children are
Other causes in older children include head injuries, loud noises (including loud music), use of ototoxic drugs Drug-Induced Ototoxicity A wide variety of drugs can be ototoxic. Factors affecting ototoxicity include Dose Duration of therapy Concurrent renal failure read more (eg, aminoglycosides, thiazides), viral infections (eg, mumps Mumps Mumps is an acute, contagious, systemic viral disease, usually causing painful enlargement of the salivary glands, most commonly the parotids. Complications may include orchitis, meningoencephalitis... read more 
), tumors or injuries affecting the auditory nerve, foreign bodies of the ear canal Foreign bodies in the ear The ear canal may be obstructed by cerumen (earwax), a foreign object, or an insect. Itching, pain, and temporary conductive hearing loss may result. Most causes of obstruction are readily apparent... read more , and, rarely, autoimmune disorders.
Risk factors for hearing loss in children include those for neonates plus the following:
Noise exposure
Etiology references
1. Goderis J, De Leenheer E, Smets K, et al: Hearing loss and congenital CMV infection: A systematic review. Pediatrics 134(5):972–982, 2014. doi: 10.1542/peds.2014-1173
2. Kimani JW, Buchman CA, Booker JK, et al: Sensorineural hearing loss in a pediatric population: Association of congenital cytomegalovirus infection with intracranial abnormalities. Arch Otolaryngol Head Neck Surg 136(10):999–1004, 2010. doi: 10.1001/archoto.2010.156
Symptoms and Signs of Hearing Impairment in Children
If hearing loss is severe, the infant or child may not respond to sounds or may have delayed speech or language comprehension. If hearing loss is less severe, children may intermittently ignore people talking to them. Children may appear to be developing well in certain settings but have problems in others. For example, because the background noise of a classroom can make speech discrimination difficult, the child may have problems hearing only at school.
Not recognizing and treating impairment can seriously impair language comprehension and speech. The impairment can lead to failure in school, teasing by peers, social isolation, and emotional difficulties.
Diagnosis of Hearing Impairment in Children
Electrodiagnostic testing (neonates)
Clinical examination and tympanometry (children)
Screening Hearing tests Screening (along with physical examination) is an important part of preventive health care in infants, children, and adolescents. To detect iron deficiency, clinicians should determine hematocrit... read more all infants before age 3 months is often recommended and is legally mandated in most US states (1 Diagnosis reference Common causes of hearing loss are genetic defects in neonates and ear infections and cerumen in children. Many cases are detected by screening, but hearing loss should be suspected if children... read more ). The initial screening test is evoked otoacoustic emissions testing Testing , using soft clicks made by a handheld device. If results are abnormal or equivocal, auditory brain stem evoked responses Testing are tested, which can be done during sleep; abnormal results should be confirmed with repeat testing after 1 month. If a genetic cause is suspected, genetic testing can be done.
In children, other methods can be used. Speech and overall development are assessed clinically. The ears are examined, and tympanic membrane movement is tested in response to various frequencies to screen for middle ear effusions. In children age 6 months to 2 years, response to sounds is tested. At age > 2 years, ability to follow simple auditory commands can be assessed, as can responses to sounds using earphones. Central auditory processing evaluation Testing can be used for children > 7 years without neurocognitive deficits who seem to hear but not to comprehend.
Imaging is often indicated to identify the etiology and guide prognosis. For most cases, including when neurologic examination is abnormal, word recognition is poor, and/or hearing loss is asymmetric, gadolinium-enhanced MRI is done. If bone abnormalities are suspected, CT is done.
Diagnosis reference
1. US Preventive Services Task Force: Universal screening for hearing loss in newborns: US Preventive Services Task Force recommendation statement. Pediatrics 122(1):143–148, 2008. doi: 10.1542/peds.2007-2210
Treatment of Hearing Impairment in Children
Hearing aids or cochlear implants for irreversible hearing loss
Sometimes teaching a nonauditory language
Reversible causes and abnormalities are treated.
If hearing loss is irreversible, a hearing aid Hearing aids Worldwide, about half a billion people (almost 8% of the world's population) have hearing loss ( 1). More than 10% of people in the US have some degree of hearing loss that compromises their... read more can usually be used. They are available for infants as well as children. If hearing loss is mild or moderate or affects only one ear, a hearing aid or earphones can be used. In the classroom, an FM auditory trainer can be used. With an FM auditory trainer, the teacher speaks into a microphone that send signals to a hearing aid in the nonaffected ear.
If hearing loss is severe enough that it cannot be managed with hearing aids, a cochlear implant Cochlear implants Worldwide, about half a billion people (almost 8% of the world's population) have hearing loss ( 1). More than 10% of people in the US have some degree of hearing loss that compromises their... read more may be needed. Children may also require therapy Treatment of Hearing Loss in Children Worldwide, about half a billion people (almost 8% of the world's population) have hearing loss ( 1). More than 10% of people in the US have some degree of hearing loss that compromises their... read more to support their language development, such as being taught a visually based sign language.
The COVID-19 pandemic required hearing specialists to develop ways of remotely monitoring and interacting with children with hearing loss. Some of these methods, eg, remote monitoring and programming of devices and online or in-app speech therapy techniques, may remain useful to patients even after pandemic restrictions are lifted.
Treatment references
1. Brotto D, Sorrentino F, Favaretto N, et al: Pediatric hearing loss management in the COVID-19 era: Possible consequences and resources for the next future. Otolaryngol Head Neck Surg 166(2):217–218, 2021. doi: 10.1177/01945998211012677
2. Marom T, Pitaro J, Shah UK, et al: Otitis media practice during the COVID-19 pandemic. Front Cell Infect Microbiol 11:749911, 2022. doi: 10.3389/fcimb.2021.749911
Key Points
Common causes of hearing loss in neonates are cytomegalovirus infection or genetic defects and in infants and older children are cerumen accumulation and middle ear infusions.
Suspect hearing loss if a child's response to sounds or development of speech and language is abnormal.
Screen infants for hearing loss, beginning with evoked otoacoustic emissions testing.
Diagnose children based on results of clinical examination and tympanometry.
Treat irreversible hearing loss with a hearing aid or cochlear implant and language support (eg, teaching sign language) as needed.
