Hearing Loss Assessment in Children

Excerpt

Hearing loss is relatively common in newborns and children, with an estimated prevalence of 1.1-3.5 per 1,000 newborns screened. Up to 20% of children are affected by some degree of hearing loss by age 18, underscoring the need for appropriate diagnostic and intervention techniques to prevent negative sequelae of hearing loss. Undiagnosed and untreated, hearing loss can have significant consequences, including speech and language developmental delays, vestibular dysfunction, increased anxiety and depression, and decreased well-being and self-esteem.

In 1993, the National Institutes of Health published recommendations that all newborns obtain routine hearing screening by 3 months of age. The Joint Committee on Infant Hearing published its first position statement in 1994, with updates made in 2000, 2007, and most recently in 2019. The 2007 guidelines called for newborn hearing screening to be performed in all newborns by 1 month of age, with definitive diagnostic audiometric testing completed by 3 months for those who did not pass, and finally, with the initiation of an appropriate intervention by 6 months of age. These recommendations have been adopted widely in the United States, with recent data indicating that 98% of all newborns completed initial screening for hearing loss within 1 month of birth. This led to the updated recommendation 2019 that screening, diagnostic testing, and intervention be completed in 1 month, 2 months, and 3 months, respectively, wherever possible.

Hearing loss may be unilateral or bilateral. Unilateral hearing loss is frequently considered less problematic than bilateral hearing loss, although more recent data has demonstrated its clinical significance. Balanced input to both ears is essential for developing binaural hearing pathways early in life. Without binaural hearing, sound localization is more difficult and can significantly affect patients, especially when trying to hear in the presence of background noise through decrements in binaural squelch. Children with unilateral hearing loss have a 10-fold higher risk of repeating at least 1 grade in school than normal-hearing children (35% vs. 3.5% respectively). Up to 40% require additional educational assistance. Unilateral hearing loss has also been reported to progress into bilateral hearing loss in 7.5 to 11% of cases, demonstrating the importance of active diagnosis and treatment of unilateral and bilateral hearing loss. Cochlear malformations such as Mondini dysplasia or enlarged vestibular aqueduct have been reported to be responsible for greater than 50% of unilateral hearing loss in children.