Imagine being in the middle of a busy city—car alarms, traffic, people talking and shouting are all noises that permeate the urban landscape. How does this auditory milieu affect a developing mind? Northewestern University’s Auditory Neuroscience Laboratory investigated how socioeconomic status and maternal education levels are related to children’s neural processing abilities. The research team, lead by Erika Skoe, assistant professor of speech, language, and hearing sciences at the University of Connecticut, found that, even when in a quiet environment, children whose mothers had the lowest levels of education experienced the highest levels of neural noise.

The researchers evaluated a group of ninth grade students. They assessed the students’ IQs, reading abilities, and levels of working memory using standardized, aged-normed tests. They also evaluated the students’ nervous system response to auditory input using passive electrophysical recordings. The students watched a self-selected subtitled movie, listening to the audio with headphones. The right channel of the headphones delivered the sound, while the left was kept clear.

To evaluate the results, the research team grouped the students by their mother’s highest level of education. They found that the students whose mothers had less education had “noisier” neural responses and performed worse on the working memory and reading assessments. Having a noisier neural response is similar to the feeling of going to a concert and experiencing ringing in the ears for hours after. While these students did not experience actual ringing in their ears, the neural effect was that of the ongoing echo of a noisy environment. When neurons have noisier input, their firing rate becomes variable, which limits the amount of sensory information that can travel through the brain.

Stated Skoe, “If your brain is creating a different signal each time you hear a sound, you might be losing some of the details of the sound. Losing these details may create challenges in the classroom and other noisy settings.” these findings may lead to understanding how experiences impact the brain and to strategies that help close the socioeconomic achievement gap.

This research is published in the Journal of Neuroscience.

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