New implantable bone conduction hearing device technology that provides hearing-impaired listeners with access to higher frequency sounds offers improved speech understanding compared to previous bone conduction devices, according to a study by University of Miami Miller School of Medicine faculty published in Hearing Research.
“The benefit of an extended high frequency bandwidth has been demonstrated in conventional hearing aids but had not yet been studied in osseointegrated bone conduction devices. These findings will help audiology providers better counsel patients considering bone conduction technology on what to expect,” said study coauthor Brianna Kuzbyt, Au.D., assistant professor of otolaryngology at the Miller School.
Osseointegrated bone conduction hearing devices are implanted into the bone behind a user’s hearing-impaired ear, with an external sound processor worn on the outside of the head. Bone conduction technology often is used when sound can’t pass through the ear normally to a functioning hearing organ, as is the case when a person is born with a closed ear canal, Dr. Kuzbyt explained. Sound vibrations are sent from the sound processor through the bones of the skull directly to the hearing organ, without needing to pass through the ear canal and middle ear.
“Bone conduction can also be used in listeners who are unilaterally deafened to reroute sound from an impaired ear to the hearing ear. The osseointegrated implant detects sounds from the hearing device on the deaf ear,” Dr. Kuzbyt said. “The sound is transmitted by way of vibration through the skull to the hearing organ of the ear with better hearing, allowing the listener to hear sounds from their impaired side.”
The condition, called single-sided deafness, usually occurs in adults but can happen in children.
“Typically, people with single-sided deafness struggle to hear and understand speech if it is toward their deaf ear, and they often compensate by turning their better-hearing ear toward the speaker. They might change where they are sitting or standing in relation to speakers, or request that speakers repeat what they said. Sometimes they may pretend to understand what was said,” Dr. Kuzbyt said. “Hearing and understanding speech becomes harder in groups, especially when there is background noise. Hearing devices that reroute sound from the impaired ear to the better ear typically allow for better access to sound and decreased listening effort.”
Historically these implant systems have only been able to amplify sound in a limited frequency range. Extending the frequency range amplified by hearing devices has the potential to improve a listener’s ability to detect and discriminate speech sounds which can lead to improved speech understanding.
New hearing aids are marketed to consumers as superior to previous technologies and this could influence people to pursue surgery or purchase a new hearing device, according to Dr. Kuzbyt.
The new study offers objective scientific research to give credibility to manufacturers’ claims, she added.
Making Providers More Informed
“It is important for health care providers to understand how new technology can help people with hearing loss, so they make more informed medical recommendations. Likewise, it’s important for people with hearing loss to understand the technology’s true benefits, so they make more informed medical decisions,” Dr. Kuzbyt said.
Researchers at the University of Miami Ear Institute are involved in several ongoing research studies in areas related to single-sided deafness and its management.
“Patients come from all over to receive top-of-the-line care in our clinic, and our continued work in this area informs our clinical work and improves our patient care,” Dr. Kuzbyt said. “Hearing Research is a scientific journal for the very people who create these hearing devices, recommend them to patients, implant them in the operating room, and test them in the research lab. We want to equip everyone, but especially this group, with information on how these devices perform and how they can help people with hearing loss.”
Hillary Snapp, Au.D., Ph.D., chief of audiology and associate professor of otolaryngology at the Miller School, is coauthor of this study.