June 2021 CTV News London
Advancements in cochlear implant research at Western University might just be music to the ears to the deaf or hard of hearing. Western researchers, working with international colleagues, have developed a new tool that helps cochlear implant patients hear their world with improved clarity.
Luke Helpard, PhD candidate at Western’s School of Biomedical Engineering, said patients with cochlear implants often process sounds that seem warped or out of tune. “We call it a pitch mismatch, where frequencies are perceived different from their natural pitch. And that may not sound like a big deal, but that can have a lot of consequences for things like speech perception, music appreciation, even sound localisation.” According to the Schulich School of Medicine and Dentistry, when cochlear implants are surgically placed, electrodes are inserted along the cochlea -- the part of the inner ear that converts vibrations into pitches of sound -- and Helpard says that until now programming has been one-size-fits-all. “Some users have qualitatively reported that a cochlear implant can sound like Mickey Mouse, or Darth Vader, or these sort of warped type of hearing where it doesn’t sound natural.”
Helpard is part of a team that has come up with a tool to mathematically program the cochlear implant for each patient’s specific needs. They’re using imaging data to customise the pitch map for each patient. A pitch map refers to how simulation frequencies are assigned to each electrode, and ultimately, how sounds are perceived by the patient. “With this new tool we’re able to model individual pitch maps relatively accurately, and much more accurately than any previous approaches,” said Helpard. “So we really think this will revolutionise how cochlear implant programming will happen.”
The project is being co-led by Hanif Ladak, PhD, a professor at Schulich and the Faculty of Engineering, along with Dr. Sumit Agrawal, an associate professor at Schulich. The new tool is currently being used in trials. In a news release from Schulich, Ladak noted they’re already seeing real world results. “Typically, when we talk about math, people can’t see how it is applicable in real life. What’s beautiful about this is that our mathematical tool has an obvious real-life application and audiologists are already beginning to evaluate it in patients.” Helpard said they’re hoping the new tool will “improve quality of life overall through speech perception, music perception, and as well the ability to perceive sounds in nature.”
Imaging data is being used to customise the pitch map for each cochlear implant patient