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Why Fingernails On a Chalkboard Sound Painful
sciencehabit writes "Some sounds are excruciating. Take fingernails squeaking on a chalkboard. The noise makes many people shudder, but researchers never knew exactly why. A new study finds that there are two factors at work: the knowledge of where the sound is coming from and the unfortunate design of our ear canals. 'The offending frequencies were in the range of 2000 to 4000 Hz. Removing those made the sounds much easier to listen to. Deleting the tonal parts of the sound entirely also made listeners perceive the sound as more pleasant, whereas removing other frequencies or the noisy, scraping parts of the sound made little difference.'"
There's certainly a psychological component. Just thinking about that noise and making the clawing/scraping motion with my hand, right now, made me react as I would hearing it for real.
-mrxak
Onions Will Kill You
Dammit no. I remember being a child and hearing that sound and cringing then finding out AFTER that I wasn't alone.
Some things just plain old suck (like fingernails on a chalkboard and communism).
crazy dynamite monkey
They've only narrowed down the class of sounds, but not why we would find those sounds so annoying.
and in 1986 no less (back when "chalkboard" still had some meaning): http://www.straightdope.com/columns/read/540/why-is-the-sound-of-fingernails-scraping-a-blackboard-so-annoying
Baby crying has a wide variation, and the fundamental frequency is (depending on who you ask) somewhere around 500Hz, but you get strong harmonics and nonlinears up in the 3Khz area. The non-linears are a strong part of the annoyance too. See for example http://ergo.human.cornell.edu/studentdownloads/DEA3500pdfs/hearing.pdf
And you are designed by millions of years of evolution to find that so annoying you will do anything to make it stop.
Isn't that just learning? You have not yet directly experienced skunk spray, so it doesn't have the same effect on you as someone who has experienced it. The area I have always lived in has a lot of skunks. Like you, the smell never bothered me all that much. Then one day our cat got sprayed, and before we knew it he was in the house. Now I absolutely can not stand that smell, no matter how far off it is.
Yeah, inflatable plastic makes a balloon-like squeal when punctured.
"I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)
My high school music teacher taught me how to make a stick of chalk squeal on a chalkboard at will.
Hold a fresh piece between your first two fingers and your thumb lightly, with the other end resting against the middle of your palm. hold the tip against the board with a sharp downward angle about the same as a backslash \, and draw a line downward. Don't press too hard or you'll dampen the resonance and get nothing. When you get the hang of it it's very easy to produce a head-splitting screech above 100dB
You don't need an audiology experiment to figure this out. Harvey Fletcher and W. A. Munson established the lab work back in 1933, resulting in the Fletcher-Munson Curve which illustrates how the sensitivity of the human ear varies at different frequency ranges and volume levels, and is most sensitive in the 2-6kHz range. It's fair to assume this range is more sensitive since it is the hardest range for predators to keep silent while stalking prey, i.e. a twig snapping.
It is believed mankind has pre-historic rodents to thank for their advanced auditory system, which developed during the 65 million year period where mammals and dinosaurs co-existed. During this time there was low oxygen content in the air, so mammals had to maintain high respiratory rates, making them easy prey for the much larger dinosaurs, whose respiratory system involved hollow bones to transport air directly throughout their bodies rather than just lungs to deliver oxygen to the bloodstream. (Birds benefited from the hollow bones to fly, but only use lungs for respiration now that oxygen levels are up.) Mammals had to forage at night and depended almost entirely on their auditory systems for defense. 65 million years of that is likely the only reason we can discern music, much less appreciate it.
As a sound engineer I can attest that the 2-6kHz range is of special significance when putting a mix together. It's usually actually more important that the 2-6kHz range of each voice or instrument be balanced against each other than each voice or instrument be of even frequency response themselves. If something is dominant in that range, it dominates the listener's attention every time. If something has a sharp spike in that range, meaning a very narrow frequency band, it will not be pleasant to the ear. If you check out the frequency response graphs of the cheaper guitar speakers by clicking on the options here, you might notice they all have spikes around 2-2.5kHz. That is why they suck.
War as we knew it was obsolete
Nothing could beat complete denial
- Emily Haines
How is the AC's comment sexist?
It appears that AC is married to someone with a harsh voice. The AC didn't claim that all women, or even all wives, have harsh voices. AC just claimed one person who AC likely spends a lot of time with has a harsh voice.
Although AC could have said "$WIFE_NAME's voice is the only sound more harsh...", that would not have conveyed that AC likely spent a lot of time with that person. For example, if AC had said "Jane's voice is the only sound more harsh...", for all we know 'Jane' could be a checker at the local Walmart and since, presumably, AC doesn't spend that much time with a particular checker at Walmart, the message would have reduced significance.
AC could have used the word spouse instead, but that's rather unnatural and unusual as most people refer to their 'wife' or 'husband' rather than their 'spouse' in normal conversation.
Not all observations or criticisms aimed at anyone but a straight white middle aged able-bodied mail is "racist" or "sexist" or "$GROUPphobic".
Why is there an "insightful" mod and why isn't it "-1"? If I wanted insight, I wouldn't be reading