Researchers Develop Soft Auditory Brainstem Implant Offering Hope for Patients

New Delhi: Researchers at EPFL’s Laboratory for Soft Bioelectronic Interfaces (LSBI) have developed an ultra-thin, flexible auditory brainstem implant (ABI) designed to restore hearing in patients who cannot benefit from traditional cochlear implants.

Published in Nature Biomedical Engineering, the study highlights a pliable implant made of micrometer-scale platinum electrodes embedded in silicone. This innovative design allows the implant to seamlessly conform to the brainstem’s curved surface, improving contact with neural tissue and potentially minimizing unwanted nerve stimulation and associated side effects.

While cochlear implants have helped millions regain hearing, they depend on an intact cochlear nerve. For patients with severely damaged or absent cochlear nerves—due to congenital conditions, tumors, or trauma—ABIs present a viable alternative. However, traditional ABIs often struggle with poor tissue conformity, limiting their effectiveness.

“Creating a soft implant that truly conforms to the brainstem is a critical step toward restoring hearing in patients who aren’t candidates for cochlear implants,” said Prof. Stephanie P. Lacour, head of the LSBI. “Our success in macaque models indicates strong potential for clinical translation.”

Instead of relying solely on surgical feasibility, the team conducted detailed behavioral experiments in macaques with normal hearing. This approach enabled the researchers to gauge how well the animals could interpret different electrical stimulation patterns, akin to natural hearing.

“Our goal was to use soft, bioelectronic materials to improve how well the electrodes match the brainstem’s shape,” said Alix Trouillet, co-first author and former EPFL postdoctoral researcher. “Better conformity helps lower stimulation thresholds and enhances the performance of individual electrodes, leading to more precise hearing.”

The soft ABI also features reconfigurable microfabrication, enabling it to adapt to different brainstem anatomies. While the findings are promising, the researchers note that more work, including clinical trials and regulatory approvals, is needed before the technology can reach patients.

This advancement marks a promising step in expanding hearing restoration options for individuals with profound hearing loss who have few alternatives today.