Toward improved measurement of infant bone conduction auditory brainstem responses

Newborn hearing screening has led to improved detection and treatment of hearing loss (HL) in infants and young children, supporting improved communication outcomes in early childhood and beyond. However, current screening protocols are not equally sensitive to all forms of HL, limiting diagnostic accuracy and, ultimately, identification of appropriate treatment options. Correspondingly, treatment outcomes in children with HL remain quite variable. One fundamental and persistent challenge is the assessment of bone conduction hearing, which is essential to differentiate conductive versus sensorineural pathology. Whereas hearing via air conduction can be effectively assessed using the auditory brainstem response (ABR), a noninvasive electrophysiologic measure, bone conduction ABR measurements suffer from comparatively poor signal quality (including significant stimulus artifact), transducer acoustic output limitations, and generally lower test-retest reliability. Here we evaluated the prospective benefits of measuring infant bone conduction ABRs using a modified bone conduction transducer designed to reduce stimulus artifact and thereby improve measurement quality. Measurements obtained using a standard bone conduction transducer were compared on several dimensions to measurements obtained using the modified transducer. Improved bone conduction measurement tools are expected to support improved detection and classification of conductive and mixed HL, leading to improved treatment outcomes for this important patient population.