A new study reveals that the human brain processes low-frequency infrasound below 16 Hz via a completely unique inner-ear mechanism, bypassing standard sensory receptors.
The Research
Carlos Jurado, postdoctoral fellow at the Norwegian University of Science and Technology (NTNU), and Torsten Marquardt from University College London published their findings in Scientific Reports. They discovered that infrasound—sounds too low for typical hair cells to detect—physically vibrates the cochlea's structural support cells instead. These support cells flex and generate local electric fields strong enough to trick nearby nerve fibers, sending alternative bio-electric signals to the brain. This explains why infrasound feels more like a physical sensation or hum than an audible sound. The pathway is non-linear: small increases in sound pressure cause a rapid, disproportionate rise in perceived volume.
Why It Matters
This mechanism provides a clear biological basis for why some people are highly sensitive to low-frequency noises like heat pumps, generators, or wind turbines, while others barely notice them. Individual differences in the density and electrical sensitivity of these support cells could explain your own sensitivity to ambient hums. Understanding this could help develop better noise assessments for workplaces and homes.
What You Can Do
If you're sensitive to low-frequency noise, consider soundproofing or using white noise to mask it. Pay attention to how your body reacts—infrasound often registers as pressure or vibration rather than sound. For a deeper look at your own auditory processing and cognitive strengths, take our free adaptive IQ test.
Source: Neuroscience News
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