A female scream. Squealing brakes. A baby crying. An electric drill. Nails on a blackboard. They all make the list. The top 10 list. The top 10 list of the most unpleasant sounds according to a study published in the Journal of Neuroscience.
Instead of torturing you with the entire list, I limited it by choosing my personal top five. You’re welcome! Just reading through the list made me cringe. I wanted to cover my ears. Turns out I’m not alone.
New research explains why we have negative emotional reactions to sounds we perceive as noise. The study found that noise really can be more than an annoyance. Noise isn’t just bad for your ears, it’s bad for your health.
“Noise is thought to cause physical and psychological stress to the body,” according to Elizabeth Masterson, Ph.D., an epidemiologist at the CDC’s National Institute for Occupational Safety and Health (NIOSH). “When you have chronic stress, it produces a chronic stress response, which can contribute to high blood pressure and cholesterol.”
Exposure to noise can elevate blood pressure, cause headaches, irritability and fatigue. Annoying sounds that leave us feeling irritable or agitated can increase our blood pressure and even change the rhythm of our heart beat, adversely affecting our overall health and well-being.
It’s Not Just the Loudness of Sound
It won’t come as much of a surprise that previous studies found that loud sounds are more bothersome than quiet ones. But new research takes that a step further, showing that in addition to loudness, the type of sound is also a factor. Listeners in the study rated high-frequency sounds (between 2,000 to 5,000 Hz) as the most unpleasant. Researchers believe that the amygdala — the part of our brain that regulates emotions — takes over the auditory part of our brains when we hear noise.
This finding helps explain why we have negative reactions to unpleasant sounds we perceive as noise. Scientists hope that more research on the interaction between the amygdala and the auditory cortex will lead to a better understanding of tinnitus and hyperacusis — disorders associated with sensitivity to sounds and that often accompany hearing loss.
One Person’s Trash Is Another Person’s Treasure
When it comes to noise, the old adage “one person’s trash is another person’s treasure” certainly applies. We can all agree that noise is unwanted, even unpleasant. What we can’t agree on is which sounds are noise. Sounds that are music to one listeners ears may sound like nails on a chalkboard to another.
Which sounds listeners classify as noise vary greatly. This probably explains the disconnect between my musical tastes as a teenager and that of my parents. They never understood why I worked one summer just to save for Metallica concert tickets.
But seriously, our brains are busy processing sound around us all the time. Our brains are even aware of unwelcome noise while we sleep.
Our brains differentiate between the sounds we want to hear and the noise we don’t. Which sounds are which are based on our personal listening preferences. While some of us love to listen to soothing white noise or a fan to fall asleep, others find the same sounds irritating.
How Noises Affect Our Bodies
Sounds that our brains perceive as noise increase irritability and anxiety. Increased levels of agitation increase the stress hormone cortisol in our bodies. Cortisol increases blood pressure and blood sugar while decreasing our body’s ability to fight disease. Increased stress increases cardiovascular risks. Loud sounds can even cause our hearts to beat irregularly. The medical term for this is atrial fibrillation. It is a scientific fact that loud sounds affect not only our moods, they can also impair our immune system.