Everyone has at least one noise that drive them bonkers. Researchers recently identified in a study some of the worst auditory offenders -- and why they might be so grating to your ears.
Scientists at Newcastle University have researched the part of the brain reacts negatively to certain sounds and even created a top 10 list of those that are the most irritating.
According to the university website, 13 people participated in the study. Of the 74 sounds they listened to, here is the breakdown of best and worst (Note: If you click on the links, you can hear the sounds):
MOST UNPLEASANT SOUNDS
6. Female scream
8. Brakes on a cycle squealing
9. Baby crying
10. Electric drill
LEAST UNPLEASANT SOUNDS
2. Baby laughing
4. Water flowing
It could be argued that the sample size of little more than a dozen participants was too small to truly categorize these as the best and worst sounds.
Researchers monitored participants' brains as they were listening to these sounds and found those that rated as more unpleasant were associated with a heightened auditory response thanks to regulation by the part of the brain that controls emotion, the amygdala. Study author Sukhbinder Kumar said it "appears there is something very primitive kicking in."
Here's more on the details:
Analysis of the acoustic features of the sounds found that anything in the frequency range of around 2,000 to 5,000 Hz was found to be unpleasant. Dr Kumar explains: "This is the frequency range where our ears are most sensitive. Although there’s still much debate as to why our ears are most sensitive in this range, it does include sounds of screams which we find intrinsically unpleasant."
The scientists believe further research down this vein could improve understanding of those with medical disorders that relate to their auditory perception, such as patients with autism.
"This might be a new inroad into emotional disorders and disorders like tinnitus and migraine in which there seems to be heightened perception of the unpleasant aspects of sounds," lead researcher Tim Griffiths said in a statement.
This research is published in the Journal of Neuroscience.