The Brain’s Built-In Noise Cancellation

The Brain’s Built-In Noise Cancellation: How Top-Down Signals Guide Auditory Processing in the Brainstem Our sensory systems, including hearing, use two main “highways” to interpret sounds: ascending pathways that carry sounds from the ears to the brain, and descending pathways that send feedback and contextual signals from higher levels of the brain back down to lower levels. While many studies have focused on how sound signals travel up through the brain, we are still uncovering how top-down signals improve hearing function at the lower levels. The dorsal cochlear nucleus (DCN) is an early auditory processing area that acts as an adaptive filter. It suppresses neural responses to self-generated sounds, such as footsteps or chewing, so they don’t interfere with external hearing. A major question is how the brain sends specific instructions to the DCN to manage these different sound frequencies. In this presentation, Emerging Research Grants (ERG) scientist Timothy Balmer, Ph.D., shares how his lab’s recent work reveals descending pathways to the DCN that could guide adaptive filtering to improve hearing accuracy. Understanding how these pathways work may eventually lead to approaches to improve treatments for auditory processing disorder, hearing loss, and tinnitus. Balmer is an assistant professor in the School of Life Sciences at Arizona State University. His 2025–2026 ERG grant in the area of Ménière’s disease is generously funded by the Salice Family Foundation. His 2022–2023 ERG grant, also on Ménière’s disease, was generously funded by an anonymous donor, and his 2017 ERG grant for a tinnitus project was generously funded by the Les Paul Foundation. HHF’s research webinars highlight the significant findings by Emerging Research Grants scientists. Our ERG program provides seed funding to early stage investigators, including in underfunded areas of otology, and these hourlong Zoom presentations underscore the critical impact this funding has had on both research advances as well as the scientists themselves. All sessions include an interactive Q&A with the speaker. The series is moderated by Anil K. Lalwani, M.D., a member of HHF's Board of Directors and the head of HHF's Council of Scientific Trustees, which oversees the ERG program. He is a professor and the vice chair for research in the department of otolaryngology–head and neck surgery, the associate dean for student research at Columbia University Vagelos College of Physicians and Surgeons, and a co-director at the Columbia Cochlear Implant Program. #research #science #funding #hearing #brain