# Why can't we close our ears? **URL:** \ **Category:** Factual Questions\ **Created:** [August 16, 2012, 7:02pm UTC](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698 "2012-08-16T19:02:53Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [August 18, 2012, 12:34am UTC](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698/21 "2012-08-18T00:34:17Z")
> [@AaronX](#): > > I thought it’s because ear plugs don’t block out much of the frequencies used for voice, but block other frequencies instead. At least, I think that’s what gun earplugs do. I don’t think so. Most isolation headphones block (or try to block) all frequencies fairly equally, and of course fail at that. The ones for musicians try harder. But they all tend to attenuate the highs most. A gunshot is full-spectrum, so good ones for guns would try to be full-spectrum. In fact, in audio circles, starter pistols are used with microphones to generate the “impulse response” from an acoustic space, like Carnegie Hall, so that they can make a reverb unit sound just like Carnegie Hall. I bet they’d use a shotgun if they could get away with it! The main reason you can still hear speech is that people are talking loud enough to be heard over the background noise. Your hearing system compensates for the overall reduction. Furthermore, in some cases (e.g., noisy bar with loud band) the reduction in all the sound reduces sound to a level where your ears are more acute – before those muscles kick in, for example. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [August 18, 2012, 9:25am UTC](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698/22 "2012-08-18T09:25:37Z")
Oh ok. Maybe I was thinking about anti sound. Does that work in that way? ---
**Author:** ![bot3](https://avatars.discourse-cdn.com/v4/letter/b/41988e/32.png) [@bot3](https://boards.straightdope.com/u/bot3)\ **Post date:** [August 18, 2012, 11:36am UTC](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698/23 "2012-08-18T11:36:12Z")
If I could, I would like implants that I could switch both my eye sight and hearing on and off. ---
**Author:** ![Freakenstein](https://avatars.discourse-cdn.com/v4/letter/f/b782af/32.png) [@Freakenstein](https://boards.straightdope.com/u/Freakenstein)\ **Post date:** [August 19, 2012, 4:50pm UTC](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698/24 "2012-08-19T16:50:29Z")
> [@Dickie.and.his.cat](#): > > I wonder if any animal can? I have read that crickets can do that. Their chirping is so loud that they would became deaf unless they disconnect something in their ears while they do it. No, I can’t cite, it was a Finnish science magazine years ago. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [August 19, 2012, 5:24pm UTC](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698/25 "2012-08-19T17:24:59Z")
> [@Learjeff](#): > > Actually, our ears have 3 different mechanisms for dealing with how loud the ambient sound level is and adjusting to them. > . . . > There’s a third which I can’t remember at present but is probably covered nicely in wikipedia. I don’t know if it is what you had in mind, but the outer hair cells of the cochlea act as selective amplifiers of certain frequencies of sound. The amplification effect is probably actively tunable - i.e., the brain sets the mechanism to amplify those frequencies iti s currently interested in. Very likely, when levels are too high, this mechanism can be turned off (or tuned to other frequencies that are not so loud). [Wikipedia does mention this](http://en.wikipedia.org/wiki/Cochlea#Amplification_by_the_hair_cells), but only briefly and superficially. > [@Kimstu](#): > > Non-biologist WAG: eyes are more delicate/exposed than ears and need more protective covering? > > The sensitive parts of your auditory equipment are tucked safely away in a narrow hole in your skull and shielded by semi-rigid folds of skin and cartilage (which also act as sound amplifiers). Additional shielding wouldn’t add much protection. > > But much of the most delicate material in your ocular equipment is right out there on the surface of your face, gathering data while directly exposed to dust and smoke and flying insects and clumsy fingers and who knows what all. Having retractable shields for the sensors is pretty important in that case. > > It’s not so much about controlling what you see (how often during an average day do you deliberately shut your eyes, after all?) as about controlling what potentially damaging substances come into contact with your eyes. Yes, but also eyelids (and blinking) play an important role in keeping the surface of the eyes wet, which they need to be. I believe that this, together with the protective mechanisms that you describe, are (as you imply) much more important than the ability to shut of visual stimulation. People can, and sometimes do, sleep with their eyes open (we had a thread on the topic a while back). However, many species (though not humans) have transparent [nictating membranes](http://en.wikipedia.org/wiki/Nictating_membrane), that cover the moistening function as well as providing at least some degree of protection. I Believe, however, that all or most species with nictating membranes do have opaque eyelids too, and I am not sure why that is. ---
**Author:** ![florabowles](https://avatars.discourse-cdn.com/v4/letter/f/a3d4f5/32.png) [@florabowles](https://boards.straightdope.com/u/florabowles)\ **Post date:** [August 20, 2012, 9:17am UTC](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698/26 "2012-08-20T09:17:36Z")
hearing is that much importent for humans ? Our ears can alert us of danger, so they’re open all the time. (Like from predators for animals and fire alarms and stuff). Just survival reasons, I guess. ---
**Author:** ![jackdavinci](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackdavinci/32/3259_2.png) [@jackdavinci](https://boards.straightdope.com/u/jackdavinci)\ **Post date:** [August 20, 2012, 10:13am UTC](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698/27 "2012-08-20T10:13:49Z")
As others have mentioned, you can close your ears. I often do, though it’s harder to keep them closed for long periods than eyes. ---
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [August 20, 2012, 10:15am UTC](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698/28 "2012-08-20T10:15:01Z")
Like all 70s boys, I daydreamed about being the Six Million Dollar Man. This was actually something I “looked forward” to being a useful function of my bionic equipment: being able to switch off my hearing completely, so, say, barking dogs wouldn’t disturb my sleep. (Apologies for not adding anything pertinent to the previous replies, which have answered the OP quite well, I’d say.) [Previous page](https://boards.straightdope.com/t/why-cant-we-close-our-ears/631698.md?page=1)