At Karolinska Institutet in Stockholm, researcher Niki Karpeta has made a discovery that could transform how doctors care for deaf and hard-of-hearing newborns: the balance system can now be tested in the first months of life using methods so gentle that babies won't even feel distressed. The finding, presented in a new doctoral thesis, reveals that many infants with hearing loss also have hidden vestibular problems—impairments of the inner ear system that governs balance, spatial awareness, and the steady gaze we take for granted when moving through the world.
For decades, when a child was born with severe hearing loss, medical attention zeroed in on hearing and speech development. But the inner ear does double duty: it controls both hearing and balance. If the vestibular system is damaged from birth, the consequences ripple across childhood. These children may start walking weeks or months later than peers, fall more frequently, struggle with everyday coordination, and sometimes develop reading and concentration difficulties once they reach school age. Yet until now, testing this crucial system in infants was either impossible or required cooperation children couldn't give.
The breakthrough lies in bone-conducted vestibular testing, known as BCcVEMP—a method that requires no active participation from the child and causes no discomfort. The test works by measuring how the body responds to vibrations transmitted through bone, revealing whether the vestibular system is functioning properly. Karpeta's research demonstrates that BCcVEMP can be performed alongside routine newborn hearing screening, making it seamlessly integrated into the standard care protocol. "We can obtain important information about vestibular function even in very young children, without causing discomfort or placing any burden on the child," Karpeta explains.
The thesis proposes a clear pathway forward: children diagnosed with hearing loss should receive vestibular assessment using BCcVEMP in early infancy, then undergo additional video Head Impulse Testing (vHIT) at around five to six months of age. This two-tiered approach allows clinicians to catch vestibular dysfunction when intervention is most effective, enabling targeted habilitation and support tailored to each child's specific needs rather than a one-size-fits-all approach.
What makes early detection particularly urgent is that vestibular function can deteriorate over time. Congenital inner ear malformations, cochlear implant surgery, or infections may all worsen balance function as children grow. The research includes a striking example: adolescents who received bilateral cochlear implants early in life showed various degrees of vestibular impairment many years later, yet many had developed effective compensatory mechanisms and functioned well despite these challenges.
The broader implication of Karpeta's work is that hearing and balance should never be treated as separate concerns. Both systems live in the inner ear; both fundamentally shape how a child moves through the world and develops cognitively. By screening both routinely and early, healthcare providers can support not just speech and hearing but motor development, confidence, and the everyday safety that allows children to play, learn, and thrive. The thesis proposes that vestibular assessment becomes standard practice for all children with hearing loss—a shift that recognizes the hidden architecture of development and gives clinicians the tools to support the whole child from birth onward.