A new soft auditory brainstem implant (ABI) developed by researchers at EPFL may revolutionize hearing restoration for people who can’t benefit from cochlear implants.
Unlike traditional rigid ABIs, this flexible device conforms to the brainstem, reducing side effects and improving sound perception. Tested in macaques, the implant allowed animals to distinguish artificial stimulation patterns nearly as well as natural sounds — an exciting sign that richer, more precise prosthetic hearing could soon reach human patients.
Over the past few decades, cochlear implants have helped many people regain hearing. These devices are considered one of the most successful applications of neurotechnology. However, they don’t work for everyone — especially for individuals whose cochlear nerve is too damaged to transmit sound signals to the brain. For these patients, an alternative option is an auditory brainstem implant (ABI), which bypasses the ear entirely and stimulates the brainstem directly.
Current ABIs, however, have limitations. They are made with rigid materials that don’t conform well to the brainstem’s curved surface. This poor contact can cause unintended nerve activation, leading to side effects like dizziness or facial twitching. As a result, many of the implant’s electrodes are switched off, and most users only perceive vague sounds with limited speech recognition.
Now, researchers at EPFL’s Laboratory for Soft Bioelectronic Interfaces have developed a new kind of ABI made from soft, flexible materials. Their thin-film device uses micrometer-scale platinum electrodes embedded in silicone, forming a highly pliable array just a fraction of a millimeter thick. This design improves contact with the brainstem and may reduce unwanted side effects by limiting stimulation to the intended nerves.
“Designing a soft implant that truly conforms to the brainstem environment is a critical milestone in restoring hearing for patients who can’t use cochlear implants. Our success in macaques shows real promise for translating this technology to the clinic and delivering richer, more precise hearing,” says Stéphanie P. Lacour, head of Head of the Laboratory for Soft Bioelectronic (LSBI) Interfaces at EPFL.
Unlike traditional rigid ABIs, this flexible device conforms to the brainstem, reducing side effects and improving sound perception. Tested in macaques, the implant allowed animals to distinguish artificial stimulation patterns nearly as well as natural sounds — an exciting sign that richer, more precise prosthetic hearing could soon reach human patients.
Over the past few decades, cochlear implants have helped many people regain hearing. These devices are considered one of the most successful applications of neurotechnology. However, they don’t work for everyone — especially for individuals whose cochlear nerve is too damaged to transmit sound signals to the brain. For these patients, an alternative option is an auditory brainstem implant (ABI), which bypasses the ear entirely and stimulates the brainstem directly.
Current ABIs, however, have limitations. They are made with rigid materials that don’t conform well to the brainstem’s curved surface. This poor contact can cause unintended nerve activation, leading to side effects like dizziness or facial twitching. As a result, many of the implant’s electrodes are switched off, and most users only perceive vague sounds with limited speech recognition.
Now, researchers at EPFL’s Laboratory for Soft Bioelectronic Interfaces have developed a new kind of ABI made from soft, flexible materials. Their thin-film device uses micrometer-scale platinum electrodes embedded in silicone, forming a highly pliable array just a fraction of a millimeter thick. This design improves contact with the brainstem and may reduce unwanted side effects by limiting stimulation to the intended nerves.
“Designing a soft implant that truly conforms to the brainstem environment is a critical milestone in restoring hearing for patients who can’t use cochlear implants. Our success in macaques shows real promise for translating this technology to the clinic and delivering richer, more precise hearing,” says Stéphanie P. Lacour, head of Head of the Laboratory for Soft Bioelectronic (LSBI) Interfaces at EPFL.
