Characterizing hearing in children and adults with Down syndrome

1. Heather Porter (Boys Town National Research Hospital)
2. Emily Buss (University of North Carolina at Chapel Hill)
3. Abigail Simon (Boys Town National Research Hospital)
4. Margaret Miller (Boys Town National Research Hospital)
5. Danielle Bishop (Boys Town National Research Hospital)
6. Lori Leibold (Boys Town National Research Hospital)

Correspondence: heather.porter@boystown.org

Background: Hearing loss occurs in 40-90% of individuals with Down syndrome, resulting in challenges to communication, learning, socialization, and employment beyond those imposed by developmental and intellectual differences alone. Previous findings suggest that while transient conductive hearing loss secondary to otitis media with effusion is common, persistent conductive, sensorineural, and mixed hearing loss also occur more frequently for individuals with Down syndrome than those without Down syndrome from the newborn period into old age. However, previous findings are largely based on medical record reviews or participants recruited from clinical samples and therefore may overrepresent individuals seeking or undergoing medical treatment. Additionally, historical data often rely on participants recruited from institutional care facilities, and therefore results may not generalize to individuals currently living with Down syndrome, the majority of whom live in community-based settings.

Research question: What is the prevalence, type, and configuration of hearing loss measured prospectively in a large, community-based sample of children and adults with Down syndrome?

Method: Participants included 107 individuals with Down syndrome ages 5.1 to 55.8 years (avg = 23.0, stdev = 11.6), recruited through organizations supporting individuals with Down syndrome and their families, community events, social media, and word-of-mouth. Audiometric assessment was completed using developmentally sensitive techniques for standard clinical (0.25-8 kHz) and extended high frequencies (11.2 and 16 kHz).

Results: On average, data show largely normal hearing sensitivity for the youngest group of participants (i.e., 5- to 10-year-olds), with evidence of high frequency hearing loss for the 11- to 20-year-old group that worsens in severity with increasing age group. Conductive hearing loss was more prevalent at low frequencies than other types of loss, and sensorineural hearing loss was more prevalent at higher frequencies, particularly for older participants. Whereas over 80% of participants had mild or greater hearing loss in one or both ears, only approximately 50% of participants or caregivers reported being aware of the presence of hearing loss.

Conclusions: Results from this study suggest that the hearing loss phenotype for individuals with Down syndrome varies by age and audiometric frequency. Evidence of high frequency hearing loss emerging in adolescents with Down syndrome suggests that audiometric assessment at these frequencies may be warranted even at relatively young ages to support early identification of potentially progressive hearing loss. Regular clinical hearing assessment is important for individuals with Down syndrome across the lifespan regardless of suspicion of hearing difficulty, emphasized by disparities in awareness of loss and diagnosed hearing impairment.