Why do some people get goosebumps when they hear the sound of scraping glass?

This sound is similar to the sound made by a certain type of monkey when it perceives a dangerous situation, so there is a theory that it is one of the conditioned reflexes left over from the evolution of humans to avoid danger. The sound of scraping glass with sharp objects such as fingernails is indeed an indescribable annoyance. In the U.S., this sound is called "blackboard screech."

What is it that makes people feel uncomfortable when they hear it? <>

Work on this poignant sound began in 1988 at the Neuroscience Institute at Northwestern University. Sound is the vibration of air, and the number of times a wave is formed by vibration in one second is called "frequency number", and the unit is expressed in hertz (Hz). For example, the sound of a large grandfather clock is low and the frequency is low, while the scream of a jet before takeoff has a high frequency number.

The human ear can hear the sound of 20Hz 20000Hz. <>

Next, focus on the sound with a slightly lower frequency number, and remove the sound with a frequency number in the range of 1000Hz and 2000Hz (the sound of 1000Hz is probably close to the highest range of soprano bel canto), and the result is that the uncomfortable sound is gone. Experiments were also carried out on the magnitude of the sound, in which there was no causal relationship. <>

Comparing this sound with the sounds of nature, it was surprising that a monkey's scream (alarm sound) when it sensed that the situation was critical was very similar to the scratching sound of this glass chalkboard. After accepting the results of this experiment, it is speculated that the creepy uncomfortable feeling we feel after hearing this sound may be the "ancient memory" of us humans when we first learned to walk on two legs, that is, the ancient memory that awakened our long-dormant "danger nearby". That is, human beings still have such a conditioned reflex in the process of evolution.

Mainly because the sound is so sharp and harsh, we get goosebumps when we listen to it.

Because that kind of sound is sharp and harsh, it is estimated that the vocal range is something that we humans cannot adapt to, and it can also be understood as a psychological conditioned reflex.

The goosebumps may be due to a certain psychological reaction to fear.

This has not been confirmed until now, but many experts believe that it may be a reflex left over from ancient times.

The sound of scraping glass sounds harsh. It is difficult for the average person to tolerate it, and hearing this sound can cause goosebumps involuntarily.

Because this sound is more harsh, people will always feel uncomfortable and get goosebumps when they hear this noisy and harsh sound.

Because this sound is particularly harsh, it is uncomfortable for most people to listen to it.

Why do some people get goosebumps when they hear the sound of sharp objects scraping glass?

Because this sound is particularly harsh, after hearing this sound, after the sound reaches the ears, the whole body will feel uncomfortable, so it will get goosebumps.

The decibel level of this sound is too high for our average human ears to bear.