[Saeema S]

Saeema S  asked the Naked Scientists:
   
Hi, I'm a 16 year old student in Canada and I'd like to know why it irritates us when nails go down a chalkboard, or squeaky sounds in general.

Thanks, Saeema                      

What do you think?

[RD]

http://www.thenakedscientists.com/forum/index.php?topic=1464.msg12609#msg12609


Personally I don't agree with the "screaming monkey" hypothesis ...
http://www.thenakedscientists.com/forum/index.php?topic=14996.0


Another hypothesis …

The squeak which triggers the response can be produced by teeth biting bone.

Perhaps the reflex has come about to prevent carnivores from damaging their teeth on bones.

[LeeE]

First thing to point out is that it doesn't bother everyone to the same degree i.e. it doesn't bother me too much, so I'll go along with RD's scepticism re the screaming monkey hypothesis, although I will admit to finding it mildly irritating, if only because it is unaesthetic.

Having said that, it does seem to be a relatively primeval response though.  Actually, considering how much variation there is in the response now, I'd hazard a guess that it may pre-date monkeys(primates), and come from an even earlier period of evolution.  It might not even be biology based (just had a weird idea about what an earthquake might sound like with no buildings or other artificial structures rattling about).

[glovesforfoxes]

It might not even be biology based (just had a weird idea about what an earthquake might sound like with no buildings or other artificial structures rattling about).

That is quite interesting to think about. What do you think it would sound like?

[LeeE]

What do you think it would sound like?

No idea; it was just a weird thought.

[thedoc]

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