Auditory Death: The Musical Killer

Hello? HELLO?!  

     Most of us loud music-loving listeners have been told at some point or another that we will surely go deaf by the time we are fifty. While some music listeners won't endure the full effects of hearing loss until their late sixties or seventies, many will lose the ability to discern tones by the time they are twenty!     In a 2011 article from the National Institute for Physiological Science, the study of sound discrimination in a noisy environment was evaluated. Similar to Dr. Dye's study of inter-aural time difference discrimination, this study, conducted by Drs. Hidehiko Okamoto, Ryusuke Kakigi, Christo Pantev, and Henning Teismann, demonstrated that "listening to loud music through earphones for extended periods in noisy surroundings can cause neurophysiological changes related to clear discrimination of sounds, even if the hearing threshold is normal" (ScienceDaily, 2011). Using magnetoencephalography to track brain activity, two groups of adults underwent an auditory test. The first group, after having listened to loud music, attempted to discern a tone of a specific frequency while watching a movie. The second group did the same, though they did not frequently listen to loud music. Those who habitually listened to loud music had a greater difficulty picking out the tone than those who did not listen to loud music. However, when given a basic hearing exam, both groups had the same results. 

     In Dr. Dye's study of inter-aural time difference discrimination, he highlights differences in subjects discernment of sound source and echo over various time differences. The goal was to map the responses of subjects according to where they believed the sound to be in space and use the graph pattern to evaluate the weights subjects give to either the sound source or the sound echo. However, while his focus is on locating a single tone and its echo, the article of concern throws a single tone among a barrage of background noise. 

     What is most interesting is the fact that both groups tested the same when given a basic hearing exam of single tone placement and recognition. This calls attention to the idea that it is not that the music listeners are losing their hearing ability, but they are losing the ability to pick out specific frequencies among the chaos of many other frequencies. The reason being that "listening to music at high volumes burdens the nerves of the brain and auditory system and can cause a decline in the ability to discriminate sounds, even if the usual hearing test results are normal and the subject is unaware of any changes" (Okamoto, 2011). 

     So instead of turning those ear buds up louder when a noisy crowd joins your El car, wait to listen to your tunes or, better yet, invest in a pair of noise canceling headphones. 



Source:
National Institute for Physiological Sciences. "High-volume portable music players may impair ability to clearly discriminate sounds."ScienceDaily, 10 Mar. 2011. Web. 10 Dec. 2012.

Hidehiko Okamoto, Henning Teismann, Ryusuke Kakigi, Christo Pantev. Broadened Population-Level Frequency Tuning in Human Auditory Cortex of Portable Music Player Users. PLoS ONE, 2011; 6 (3): e17022 DOI:10.1371/journal.pone.0017022

Dye, Raymond. "Analytic vs. Synthetic Binaural Processing."Parmly Hearing Institute and Loyola University of Chicago. PowerPoint.