Noise Sensitivity Linked to Changes in How the Brain Processes Sound
Summary: A new study examines how noise sensitivity appears in the way the brain encodes and responds to auditory information.
Source: University of Helsinki.
Many people feel strong discomfort from everyday sounds and describe themselves as being sensitive to noise. Previous work has shown that noise sensitivity increases the risk of negative health effects such as sleep disruption and cardiovascular strain, and that part of the variability in sensitivity may be rooted in genetics. The new study reported here investigates whether noise sensitivity is reflected in how the central auditory system processes sounds.
Researchers from the University of Helsinki and Aarhus University examined neural responses to sound in individuals with differing degrees of self-reported noise sensitivity. Using combined magnetoencephalography and electroencephalography (M/EEG) measurements, the team tested how the auditory cortex reacts when new sound features are introduced into a sequence of repetitive sounds.
Key Findings
The study found that individuals who report higher noise sensitivity display altered sound feature encoding in the auditory cortex. Specifically, their neural responses to novel sound elements embedded among repetitive sounds were reduced compared with less sensitive individuals. This attenuation was most pronounced when the novel sound was perceptually noisier than the surrounding sounds.
At first glance, reduced neural responsiveness to new, noisier sounds may appear counterintuitive. The researchers propose a plausible explanation: when the surrounding soundscape is unpredictable or contains frequent variations, the brain may lower its sensitivity to incoming auditory information as a protective mechanism. In other words, for noise-sensitive individuals it may be harder to form accurate predictions about changing auditory environments, and the brain may downregulate responsiveness to prevent constant overreaction to noise.
Implications and Context
These results move the understanding of noise sensitivity beyond the notion of a simple negative attitude toward sound. The findings point to measurable differences in central auditory processing that correlate with subjective sensitivity. If replicated and extended, such objective neural markers could complement self-report questionnaires and improve identification of people at higher risk of noise-related health impacts.
The study’s results have relevance beyond basic neuroscience. They may inform public and occupational health policies by highlighting the need to consider individual differences in noise sensitivity when planning noise control and designing living and working environments. Recognizing and accommodating noise-sensitive people could help reduce stress, improve sleep, and lower the broader health burden associated with environmental noise.
Study Details and Collaboration
The research was carried out at the Cognitive Brain Research Unit (CBRU) of the University of Helsinki in collaboration with the University of Helsinki’s Department of Public Health and the CICERO Learning Network, the BioMag Laboratory, and the Center for Music in the Brain at Aarhus University, Denmark. The first author of the study is doctoral student Marina Kliuchko from the University of Helsinki.
While the results point to altered auditory cortical processing in noise-sensitive individuals, the authors caution that further studies are needed to determine causality: it remains unclear whether these brain differences cause noise sensitivity or reflect adaptive changes that develop in response to prolonged exposure to sound. Either way, the study clarifies that noise sensitivity has a physiological basis that warrants attention in scientific research and in practical noise management.
Abstract
A window into the brain mechanisms associated with noise sensitivity
Noise-sensitive individuals tend to experience stronger negative emotions from unwanted sounds and are more vulnerable to adverse health outcomes related to noise. Because noise sensitivity does not appear to stem from peripheral hearing problems, this study investigated whether differences in central auditory processing relate to individual noise sensitivity. Using combined EEG and MEG, the researchers measured neural sound-feature processing and found that higher noise sensitivity is associated with altered sound encoding and reduced discrimination of sound noisiness in the auditory cortex. These findings take an initial step toward objective indicators of noise sensitivity and may help guide strategies to prevent noise-related harm in susceptible populations.
Citation: “A window into the brain mechanisms associated with noise sensitivity” by Marina Kliuchko, Marja Heinonen-Guzejev, Peter Vuust, Mari Tervaniemi & Elvira Brattico, Scientific Reports. Published online December 15, 2016. DOI: 10.1038/srep39236.
The research advances understanding of the neural basis of environmental sensitivity and highlights the potential value of integrating objective neural measures with self-report assessments when addressing noise-related health risks.