Breadcrumb

Ann-Charlotte Persson: Measuring outcomes from bone conduction hearing aids

Published

For certain types of hearing loss, traditional air-conduction hearing aids is not an option. Instead, bone-conduction hearing devices can be used. Ann-Charlotte Persson has developed a method to objectively measure the audibility of patients who have received bone-conduction hearing devices. With this new approach, the hearing aid can be tailored individually to maximize effectiveness.

Image
Ann-Charlotte Persson is an audiologist at the Audiology Clinic in Gothenburg and a doctoral candidate at the Institute of Clinical Sciences.

ANN-CHARLOTTE PERSSON
Dissertation defense: 24 May 2024 (click for details)
Doctoral thesis: Objective and subjective outcomes from Bone Conduction Hearing Devices
Research area: Otorhinolaryngology
Sahlgrenska Academy, The Institute of Clinical Sciences

Conductive hearing loss occurs when something obstructs sound from reaching the inner ear. This could be issues with the eardrum or the ear canal. Combined hearing loss means there’s both a barrier to conducting sound to the inner ear (conductive) and problems with the inner ear or auditory nerve not functioning properly.

“For patients with conductive or combined hearing loss who can’t benefit from traditional air-conduction hearing aids, bone-conduction hearing aids are often the best solution. The current advancements in bone-conduction hearing aids are increasingly leaning towards active transcutaneous hearing implants, and it’s crucial to evaluate new methods,” says Ann-Charlotte Persson, an audiologist at the Audiology Clinic in Gothenburg and a doctoral candidate at the Institute of Clinical Sciences.

Figure 5, page 22 in the thesis. The compete set-up (a) for measurements with the skin microphone (b), which is placed on the forehead and held in place by a softband (c). For extra shielding, an earmuff (d) is placed over the skin microphone.

A device beneath the skin

In an active transcutaneous bone-conduction implant, the magnet and the transducer is implanted under the skin, behind the ear. The hearing aid, which also contains a magnet, is attached to the skin and the microphones picks up the sound which is then converted into vibrations and transmitted through the bones directly to the inner ear.

What is your research about in brief?
“The aim of my thesis was to explore patients’ audibility and experiences using an active transcutaneous hearing device, the Bone Conduction Implant ( BCI), and to develop a new method for objectively verifying the audibility of patients using bone-conduction hearing devices.”

Image
Cover image of the thesis. Ear with a bone conduction hearing device. Illustration by Ann-Charlotte Persson.

“Effective and Safe”

What are the key research findings, and how can they benefit patients?
“The overarching results showed that BCI can be an effective and safe treatment for patients with conductive or mild to moderate combined hearing loss. In interviews, BCI users reported that the sound processor is easy to use and manage,” says Ann-Charlotte Persson, continuing:

“The new method, utilizing a skin microphone, can be used to measure the individual dynamic range and audibility of patients using bone-conduction hearing aids. The skin microphone can also detect and improve suboptimal fittings.”

“Rewarding to develop a new method”

What has been rewarding and challenging about your doctoral project?
“It has been incredibly rewarding and challenging to develop a method to objectively measure the amplification a patient receives through their bone-conduction hearing aid. Clinically, this method will enable audiologists to verify that a hearing aid fitting is optimal for the individual patient. That’s something we can’t do today.”

Text: Jakob Lundberg