Neurophysiological and psychoacoustical changes after exposure to modified pink noise by frequency responses of headphones

Sound can be described as the journey of energy traveling as waves into the auditory system. The way this energy changes before being interpreted by the human brain is affected by many physical factors, particularly the response of audio systems. Audio devices such as headphones are variables that are not considered in many studies concerning acoustic therapies, which pursue the betterment in many aspects of human behavior. This work aims to explore neurophysiological and psychoacoustical responses after a month of daily exposure to pink noise sounds -stimuli psychoacoustically adjusted to the human hearing and neutral in terms of emotions for the Mexican population- modified by the frequency responses of different headphone models (i.e., different frequency content). Twenty-four participants were recruited for this study following a thorough inclusion process. While performing a five-alternative forced-choice psychoacoustic discrimination test (5-FC), the electrical activity of partic-ipants was recorded before and 30 days after exposure to pink noise. Event-related potentials (ERPs) were compared to the 5-FC outcome. The results indicated a greater area under the curve of ERPs in partici-pants assigned to the headphone model group that negligibly modified the frequency content of pink noise. A greater area could be interpreted as a broader flux of information in the whole cortex, meaning a greater cognitive process for interpreting and discriminating pink noise sound, and a significant contri-bution to neuroplasticity caused by constant auditory stimulation. (c) 2023 Elsevier Ltd. All rights reserved.

Automated summary

This study aimed to investigate the neurophysiological and psychoacoustical responses after a month of daily exposure to pink noise sounds with modified frequency responses of different headphone models. The results indicated a greater area under the curve of event-related potentials (ERPs) in participants assigned to the headphone model group that negligibly modified the frequency content of pink noise, suggesting a broader cognitive process and significant neuroplasticity caused by constant auditory stimulation.