Everyone just cringes at the screeching sound of fingernails scraping on a chalkboard. There’s no surprise there that the sound it makes is unpleasant to the ears but no one even bothered to wonder why. But for Michael Oehler, a musicologist from the Macromedia University for Media and Communication and Christoph Reuter, also a musicologist from the University of Vienna, there is a need to know the reason for such reaction and it all boils down to human anatomy and psychology.
The latest study by Oehler and Reuter involved using other sounds that elicit the same reaction as the sound made by scraping on a chalkboard, such as styrofoam squeaking and a fork scraping on a plate. Some of the subjects know where the sound is coming from while others were told that they are listening to a musical composition. The participants were then asked to identify the worst sound they have heard. At the same time, the researchers monitored heart rate, an electrical conductivity of skin and blood pressure to see signs of distress.
The study found that unpleasant sounds like fingernails screeching on a chalkboard can cause a physical reaction.
The study found that unpleasant sounds like fingernails screeching on a chalkboard can cause a physical reaction; there were significant changes in skin conductivity. In addition, the frequencies of those unpleasant sounds are within the frequency range of human speech, which is between 2,000 and 4,000 Hz. Eliminating the frequencies make the sounds easier to listen to but eliminating the noisy, distinct scraping sound did not make a difference.
Psychology also played a role in the study. Participants who knew that the sound came from fingernails scraping the chalkboard rated the sound as more unpleasant compared to if they believed the sound was part of a musical composition. Despite thinking that the unpleasant sound came from a musical piece, the skin conductivity still changed, which only means that the physical response remained.
According to researchers, the shape of the ear canal could be responsible for the retained physical reaction
According to researchers, the shape of the ear canal could be responsible for the retained physical reaction. Previous studies exhibited that the shape likely amplified the frequencies between 2,000 and 4,000 Hz. Scraping your fingernails on the chalkboard results to an amplified sound that can be painful to the ears.
This Amazing Korean Rolling Barrier System Will Save Millions of Lives
Road safety is a huge concern and Korea’s road barriers look like a great solution towards preventing accidents.
Did you know that up to 1.25 million people die due to road accidents each year? One means of preventing this is installing strong metal bars or guardrails along the side of the road to deflect vehicles back into the roadway. However, the performance of these guardrails is affected by the size and speed of the vehicle that crashes into it.
In order to address this problem, South Korean company ETI (Evolution in Traffic Innovation) has designed a barrier system that not only absorbs impact energy, but converts it into rotational energy. When a vehicle hits the barrier, the rotational energy propels it forward instead of completely stopping it, thus lessening the potential injury of the people in the vehicle.
The rolling barrier keeps the vehicle slowly still in motion, thus preventing it from coming to a complete and abrupt stop.
Scientists Invent New Device That Can Diagnose 17 Diseases With a Single Breath
Is this the future of diagnosis?
Screening for some 17 diseases has never been this fast and efficient.
A device invented by a multinational team of scientists can detect 17 diseases through analyzing patterns of exhaled molecules. The technique of assessing a patient's breath to diagnose an illness is an ancient practice, dating back from about 400 BC. Physicians then can determine a patient's disease based on the odor of one's breath or of the body fluids.
The team, led by scientist and engineer Hossam Haick from Technion−Israel Institute of Technology, notes that:...
Scientists Compare Matter and Antimatter for the First Time Using Light Spectrum
Does antimatter matter?
Theory suggests that when the Big Bang occurred, equal amounts of matter and antimatter were created. However, such matter-antimatter symmetry is being challenged as the amount of matter in the universe is considered to exceed that of antimatter.
We all know that matter is anything that occupies space and has mass. Antimatter, on the other hand, is the counterpart of matter. An atom is composed of a positively-charged nuclei called proton and is orbited by negatively-charged particles called electrons. In the case of the antimatter, it's the other way around. An atom of an antimatter consists of a negatively-charged nuclei called antiproton and positively-charged electrons called positrons. Now, in spite of being counterparts, matter and antimatter may have a permanent hate-and-only-hate type of relationship, as both will be annihilated once they come in contact with each other and result in the release of a significant amount of energy.