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.'"

Comments

Just thinking about it

[mrxak]

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.

Re:Taught?

[decipher_saint]

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).

The Straight Dope ...did it

[smoothnorman]

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

That's Baby Crying Frequency

[Sarusa]

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.

Re:My wife's voice

[MobileTatsu-NJG]

Yeah, inflatable plastic makes a balloon-like squeal when punctured.

Re:My wife's voice

[uncqual]

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".