Clinical characteristics of asymmetric hearing loss in children from a large pediatric cohort

Asymmetric hearing loss (HL) is a common pediatric condition, characterized by differences in HL severity between both ears. Anamnestic and audiologic profiles of affected children are sparse, hindering development of evidence-based clinical guidelines.

Clinical characteristics for children with bi- and unilateral asymmetric HL were retrospectively obtained from a register of children with permanent HL in Germany. Cohorts were stratified by laterality (uni-/bilateral) and presence of comorbidities (with/without). Between-group differences were assessed using absolute standardized mean differences.

Here we show, across uni- and bilateral groups, family history of HL is reported for approximately 25% and comorbidities for 40%-50% of children. Children with bilateral HL have a higher proportion of pre-/perinatal risk factors (e.g., hypoxia, artificial ventilation) than children with unilateral HL. Hereditary HL is more common in children with bilateral HL, whereas unexplained causes of HL is more frequent in unilateral cases. Sensorineural HL is predominant across groups; conductive or combined HL occurs more often in children with unilateral HL and comorbidities. Sloping and flat audiogram configurations are common across groups, though many children also exhibit other shapes. Notably, 60% of children with bilateral HL present different audiogram configurations in their left and right ears.

Children with asymmetric HL represent a heterogeneous population with diverse clinical characteristics. This study highlights the need for comprehensive audiologic examination and tailored technical intervention. Bilateral asymmetries may pose greater clinical challenges compared to unilateral cases, due to higher incidence of comorbidities and risk factors as well as the high incidence of inter-aural differences in audiogram configurations.