Why do we hate the sound of chalk on blackboard?

[joeywrighty]

Hi everyone,

 

I'm new here, but it's an interesting place!

 

I'm trying to find out why humans famously don't like the sound of chalk on a blackboard, knives scraping on plates, nails scraping on plastered walls, etc. The current 'accepted' theories for our reaction are a mixture between an evolutionary defence mechanism (the sounds share properties with animal screams) and the frequency of these sounds being within the range of human speech, hence our ears have evolved to amplify those frequencies.

 

I've embedded six 'nasty' recordings and corresponding edits here - http://helios.hud.ac.uk/u0852268/

 

If anyone has a few minutes it would be great if you could take part, simply grade each edit from one to five in comparison with the reference. 1 being much more horrible than the reference, 2 slightly more horrible, 3 middle ground, 4 slightly less horrible, and 5 much less horrible than the reference.

 

have fun!

 

thanks a lot

[questionposter]

Scientists don't really know for sure why humans think sounds sound the specific way they do, we can only do maybe some basic brain scans to determine that people's brains associate different sounds with different things. In the case of a chalk board, it is likely just a subconscious reaction to something that may possibly damage ear drums with long exposure or possibly is a sound that triggers a mechanism of response of strong dislike that was genetically formed many hundreds of years ago as some kind of warning against things like predators.

Edited March 21, 2012 by questionposter

[Carvone]

Trained anticipation of an event like Pavlov`s dog salivating at a bell associated with forthcoming food, only this time we shreek at the thought of a an upcoming, painfully-boring lecture.

[Joatmon]

Trained anticipation of an event like Pavlov`s dog salivating at a bell associated with forthcoming food, only this time we shreek at the thought of a an upcoming, painfully-boring lecture.

 

I can tell you that the painfully boring lecturer also doesn't like the sound - perhaps it reminds him of a bolshie lot of students!

 

"bolshie, bolshy [ˈbɒlʃɪ] (sometimes capital) Brit informaladj1. difficult to manage; rebellious"

Edited March 21, 2012 by Joatmon

[khaled]

I know that sounds that effects the body are related to the brain

 

"bolshie, bolshy [ˈbɒlʃɪ] (sometimes capital) Brit informaladj1. difficult to manage; rebellious"

 

That's a slang word, trying to say "Bullshit" in a more civil way

[Joatmon]

That's a slang word, trying to say "Bullshit" in a more civil way

I was in the army forces so I have much experience of bullshit - we might have felt bolshie when having to experience it, but they are not the same.

Edited March 22, 2012 by Joatmon

[Xittenn]

I believe the reason for this relates to threshold of hearing. The closer a sound comes to the upper limit of frequency range of human hearing the more irritating it becomes. In the case of chalk, a broad spectrum of tones are generated near this threshold which mar the nervous system. The reaction is most likely a neural response in the midbrain and medulla, possibly a nervous response that is generated by a filter in the cortex that says I can't identify this sound please respond!

[Joatmon]

I believe the reason for this relates to threshold of hearing. The closer a sound comes to the upper limit of frequency range of human hearing the more irritating it becomes. In the case of chalk, a broad spectrum of tones are generated near this threshold which mar the nervous system. The reaction is most likely a neural response in the midbrain and medulla, possibly a nervous response that is generated by a filter in the cortex that says I can't identify this sound please respond!

 

Sounds rather like Dubstep

 

Xittenn - Added something more pleasant for you in "what are you listening to right now"

 

 

Edited March 22, 2012 by Joatmon

[Xittenn]

Astute observation old chap . . . Dubstep and the Trance/Rave genres do employ this very technique in their formal presentation. Often in a live performance the artist will push into these frequencies at a climatic point in their set such that its audience is subjected to a very similar response. The difference here is usually in the coherence of the pattern of which the brain must analyze, where in Dubstep and more so Trance/Rave this tends to be highly coherent and therefore the response tends to in turn be more coherent and often more pleasant. In this case its sort of a pleasurable pain . . .

[questionposter]

I believe the reason for this relates to threshold of hearing. The closer a sound comes to the upper limit of frequency range of human hearing the more irritating it becomes. In the case of chalk, a broad spectrum of tones are generated near this threshold which mar the nervous system. The reaction is most likely a neural response in the midbrain and medulla, possibly a nervous response that is generated by a filter in the cortex that says I can't identify this sound please respond!

 

Hmm, what your saying isn't entirely true, because I can play a guitar and play so high up on the guitar fret that it approaches the limit of the frequency of human hearing, and even go beyond it, and it doesn't sound terrible at all.

[Xittenn]

Hmm, what your saying isn't entirely true, because I can play a guitar and play so high up on the guitar fret that it approaches the limit of the frequency of human hearing, and even go beyond it, and it doesn't sound terrible at all.

 

Doesn't it? I think volume is also an important part of these statements.

 

Sorry you said terrible . . . I explained what you are referring to in my second post!

 

It is obviously more complicated and not even entirely understood, but there is in fact much consensus on this subject.

 

** or better yet not what you are referring to but the outcome of the line of thought

 

Another thing too with music is that involves emotional response which suggests the inclusion of the amygdala.

[Superfusion]

Dont know exactly what the reference thing is but i will rate on how bad they are.

 

1. /2/

 

2. /2/

 

3. /3/

 

4. /2/

 

5. /2/

 

6. /2/

 

7. /3/

 

8. /2/

 

9. /2/

 

10. /2/

 

11. /2/

 

12. /2/

[Suxamethonium]

Just I thought but if I was to stare into a bright light- it 'hurts' my eyes. Perhaps this kind of 'over-sensory' stimulation is also partly responsible in this situation?

[Weirdmaskman]

If I had been asked ordinarilly, I would have said they propagate irregular sound waves which are unpleasant to the sense of hearing

[questionposter]

Perhaps it has more to due with how the physical vibrations themselves effect you. Perhaps some random vibrations generated by a chalk board contain such a concentrated amount of energy they damage your ear drums, similar to how gamma rays contain a very large amount of energy in a much more localized space and thus damage your skin and cells, while on the other hand you could be hit with an equivalent amount of energy in the form of various radio waves and pretty much nothing would happen.

Edited April 14, 2012 by questionposter