View previous topic | View next topic

Helium

Page 6 of 8
Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8  Next

PDR
648445.  Mon Dec 21, 2009 7:47 am Reply with quote

Women can hear the sound of someone else unwrapping chocolate at levels down to -20dB or more.

PDR

 
Celebaelin
648454.  Mon Dec 21, 2009 8:19 am Reply with quote

suze wrote:
And accordingly, there are some people who can hear a sound quieter than the reference for 0 dB. Those people are most often girls under about 12, but not always.

I suppose that makes sense evolutionarily speaking.

Quote:
The jaguar does not need to hear you when it stalks you from the shadows.
Ancient Aztec Proverb

Or at least it should be.

 
gruff5
648523.  Mon Dec 21, 2009 12:14 pm Reply with quote

Celebaelin wrote:
I suppose that makes sense evolutionarily speaking.

Why? I would have thought they'd be among the least-pressured to be so equipped.

 
suze
648548.  Mon Dec 21, 2009 1:37 pm Reply with quote

Young adult women do in fact have more acute hearing than men the same age. A lot of the research into this has used subjects aged 18-25, simply because such are readily available in universities, and the women are usually shown to have an advantage of about 15%. That advantage increases over time - a man's hearing deteriorates both more and more quickly as he ages*.

Quite why this should be so is not fully understood. One common suggestion though is that it's so that women can hear their infants crying, while their menfolk can stay asleep.

It has also been demonstrated that a woman's hearing becomes more acute still at around the time of ovulation. Some women claim that they can both hear and feel their own ovulation; there is some skepticism about that, but it has been tentatively posited as the reason for the phenomenon. That is to say, upon noting ovulation, it's sex o'clock. (Or not.)

The range which we can hear changes as we age - children can often hear high frequency sounds which most adults can't (ultrasonic dog whistles, for instance), and women can often hear higher frequencies than men.

Accordingly, it's unsurprising that young girls tend to have the most acute hearing - especially at high frequencies, but in fact at all frequencies. Some individuals with hyperacusis are reckoned to be able to hear a sound at -40 dB in laboratory conditions (although this is slightly speculative, because the measuring instrumentation isn't very accurate below -10 dB).

It would be nigh on impossible to prove by experiment, but the most acute hearing of all would probably be found in a girl at the time of her first ovulation.


* Except in very noisy environments such as heavy industry. It seems that women are more likely than men to suffer damage to their hearing in such environments.

 
soup
648565.  Mon Dec 21, 2009 2:43 pm Reply with quote

suze wrote:


Some individuals with hyperacusis are reckoned to be able to hear a sound at -40 dB in laboratory conditions (although this is slightly speculative, because the measuring instrumentation isn't very accurate below -10 dB).



My son has hyperacusis, a loud noise causes him actual pain, and his hearing is fantastic, he can hear things two or three streets away, long before anyone else in the family can hear anything. He has a thing which looks like a hearing aid but it actually generates 'white noise' this is an attempt for his brain to 'turn down the volume control in his head' [1]. He now uses it pretty much as a security blanket, in situations we know are likely to have loud unexpected noises he wears his noise generator, and even switched off it seems to calm him.

[1] This was how the audiologist explained it to us so it is likely this is only a surface definition for laymen.

 
gruff5
648873.  Tue Dec 22, 2009 8:54 am Reply with quote

suze wrote:
Quite why this should be so is not fully understood. One common suggestion though is that it's so that women can hear their infants crying, while their menfolk can stay asleep.
.

Well, even in the undeveloped world, there aren't many girls who give birth under 12. And in our evolutionary environment (caves & huts, rather than sprawling mansions), I don't think either parent will have found it a struggle to hear a crying child. :-(

But a grown man hearing the subdued sounds of the movement of prey or predator whilst on a hunt - now, that's when seriously acute hearing will be most handy!

 
suze
648901.  Tue Dec 22, 2009 9:56 am Reply with quote

gruff5 wrote:
Well, even in the undeveloped world, there aren't many girls who give birth under 12.


No indeed, and in fact girls who give birth at very young ages are probably more common now than they ever were - there's plenty of evidence to suggest that things like improved diet and healthcare in the modern age have led to puberty happening earlier than it used.

But the research suggests that both women in general and children in general have better hearing than men in general and adults in general. Accordingly, female children would be expected to have the best hearing of all - and such indeed seems to be the case.

 
Celebaelin
648906.  Tue Dec 22, 2009 10:05 am Reply with quote

gruff5 wrote:
Celebaelin wrote:
I suppose that makes sense evolutionarily speaking.

Why? I would have thought they'd be among the least-pressured to be so equipped.

Young girls are likely to be amongst the weakest members of any group, particularly if under 12, and would consequently be preferentially targetted by predators so there is a selection pressure towards sharper senses to alert them if they are being hunted ie the ones with poorer hearing are 'all' dead so they don't get to breed. You would expect this tendency to manifest broadly in inverse relation to physical stature in a population subject to predation if this logic holds true. Since beyond a certain stage the individual is no longer the target of choice for predators there is a reduced necessity for acute senses and the selection for them thus tails off. One would, by extension, expect eyesight to follow a similar pattern although since eyesight is our primary sense and is used eg in hunting (not that the other senses aren't used, just not as much; hearing is comparitively short range and in my experience largely defensive) the effect would not be expected to be as marked.

Whether increased sensory acuity derived from predatory-prey environments will eventually spread through the population is another question; only if there is positive selection pressure for it to do so is the simple answer.


Last edited by Celebaelin on Tue Dec 22, 2009 10:09 am; edited 1 time in total

 
Davini994
648907.  Tue Dec 22, 2009 10:06 am Reply with quote

Is it perhaps a gossip related skill?

 
PDR
648911.  Tue Dec 22, 2009 10:12 am Reply with quote

suze wrote:
One common suggestion though is that it's so that women can hear their infants crying, while their menfolk can stay asleep.


No, you're wrong there Suze. My wife informs me (frequently, and in the strongest possible terms) that the reason why husbands aren't awakened by the sound of a child crying is that we are lazy, selfish, heartless brutes who simply don't care enough about our children. As she also informs me that wives are utterly infallible on such matters any scientific evidence that might challenge this reality is clearly male propaganda written by husbands who should be caring for their children rather than contriving lies to justify their selfish, uncaring natures.

I thought all parents knew this?

PDR

 
Celebaelin
648913.  Tue Dec 22, 2009 10:14 am Reply with quote

Mysogyny and mysandry notwithstanding I think very young girls tend to be quieter do they not? Quieter than bigger/older girls and generally quieter than boys - who knew that the explanation was that noisy little girls get eaten?

 
PDR
648918.  Tue Dec 22, 2009 10:20 am Reply with quote

Little girls tend to get eaten because they're made of sugar and spice, and predators generally have a sweet tooth because the sugar gives tham rapid, short-burst energy to power their attacks. The slugs, snails and puppy-dog's tails which comprise the little boy's physiology take longer to digest and so are not as useful to the aggresive predator. Hence evolution favours the predator with the sweet tooth, to the detrioment of the female prey.

This model also explains why evolution has resulted in a tendency towards laddism amongst teenage girls - the "lassish" ones are more likely to get eaten, so it's clearly a survival characteristic.

PDR

 
gruff5
648996.  Tue Dec 22, 2009 1:07 pm Reply with quote

Was watching a programme on the Sundarbans t'other night. The mangrove tree coastal area of Bangladesh that hosts an endangered population of Bengal Tigers.

A lot of villagers are lost every year to tiger attacks, and the attacks are increasing as the mangroves come under increasing pressure.

The docu makers interviewed the relatives of the dead and they were all wives who had lost husbands. The husbands had gone off into the mangroves to collect crabs, go fishing, and such and been taken by tigers. There were no stories shown of tigers coming into the village to grab young girls.

I expect it has always been so.

 
Celebaelin
649004.  Tue Dec 22, 2009 1:20 pm Reply with quote

Only since humans started to have villages, which is relatively recent.

 
Davini994
649013.  Tue Dec 22, 2009 1:58 pm Reply with quote

Is it?

 

Page 6 of 8
Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8  Next

All times are GMT - 5 Hours


Display posts from previous:   

Search Search Forums

Powered by phpBB © 2001, 2002 phpBB Group