A complex train of thought on entrainment and auditory information processing

Imagine you’re in a train station. You can hear a screeching locomotive, a musician’s guitar, and your neighbor’s phone conversation. Discerning each sound and processing the information is a complex ability that arises from many intertwined auditory components.

Bastian Epp and Mikkel Berrig Rasmussen found that entrainment, the process whereby one periodic system encompasses another to become synchronized, is a promising component of how the inner ear and brain oscillate to process information. In the scenario of hearing damage, without entrainment, the ability to process separate sounds simultaneously is damaged.

Incorporating entrainment into auditory models is “like going from classical mechanics to quantum mechanics,” said Epp. The phenomenon also occurs during sleep cycles and fireflies blinking.

“It’s a little bit more intricate, but at the end of the day, there are certain things that just fit better to nature,” said Epp.

The researchers began by analyzing how the oscillating components of the inner ear work in isolation for bullfrogs and mammals, then how they sync up when connected one by one. They then designed numerical simulations that oversimplified hearing in such animals to estimate the theoretical limit on auditory information an organism could process. The team found that including entrainment effects in their model mirrored an organism’s true information processing abilities, while eliminating entrainment required additional model components.

Acknowledging entrainment’s importance could one day help diagnose individuals with minor hearing damage that causes sounds to mush together, said Epp. And because entrainment connects to information processing in the brain, “suddenly we have a direct link from peripheral hearing damage to perception,” he said. In time, better hearing aids should follow.

Source: “Entrainment effects and information processing in coupled oscillator models of auditory biomechanics,” by Bastian Epp and Mikkel Berrig Rasmussen, Chaos (2026). The article can be accessed at https://doi.org/10.1063/5.0293621 .