# Would noses work better if they were spaced further apart, like ears? **URL:** \ **Category:** Factual Questions\ **Created:** [August 26, 2012, 9:12pm UTC](https://boards.straightdope.com/t/would-noses-work-better-if-they-were-spaced-further-apart-like-ears/632752 "2012-08-26T21:12:38Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 27, 2012, 8:27am UTC](https://boards.straightdope.com/t/would-noses-work-better-if-they-were-spaced-further-apart-like-ears/632752/21 "2012-08-27T08:27:33Z")
> [@Reply](#): > > Why couldn’t you just smell it with one nostril? How does stereo smelling help up close? It’s not a stereo effect. It’s a simple doubling of the scent receptors. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [August 27, 2012, 9:18pm UTC](https://boards.straightdope.com/t/would-noses-work-better-if-they-were-spaced-further-apart-like-ears/632752/22 "2012-08-27T21:18:49Z")
> [@njtt](#): > > Triangulating over what, 5 millimeters or so? Not much directional information there, let alone range information. > > Snakes sense the direction of chemical stimuli the same way that we, and all other animals, do, by moving their heads and their tongues around to find out which orientation provides the strongest signal. Why do you think they dart their heads and tongues, around so much? Hold a snake’s head (or a human’s, or a dog’s) still, and they will be very poor at judging the direction of the source of a smell (or a sound, come to that). You make a reasonable argument. And yet, I’ve never seen a discussion of a snake’s tongue or sense of smell that doesn’t mention the tips being used to perceive the direction of the scent. If this is an incorrect belief about snakes, then it seems to be extremely wide spread. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [August 27, 2012, 11:13pm UTC](https://boards.straightdope.com/t/would-noses-work-better-if-they-were-spaced-further-apart-like-ears/632752/23 "2012-08-27T23:13:06Z")
> [@Reply](#): > > Is this really a “paradigm”? I don’t think I’ve ever thought to myself “hmm, I better not move my head or I’ll lose the signal”. Every time I want to locate the source of a sound, I move my head around… I thought it was instinctual? Yes of course. In actual fact people (and other animals) do instinctively move their sense organs in order to hear, see smell, etc, better. That is my point. The “paradigm” I was referring to is one that infects popular science _accounts_ of perception, and, until very recently, dominated the research literature too. Your actual perceptual behavior isn’t affected by it, but the behavior of science writers and actual scientists is. Experiments on human perception often went to great lengths to keep their subjects’ heads (and eyes, or whatever) still, and, inevitably, found that human perception in the lab was a lot less capable than it seemed to be in normal experience. For a long time the conclusion drawn was that normal experience must be wrong (like the famous, though apocryphal story of the bumblebee being unable to fly). Actually, this sort of thing has still not died out, even in the research literature, but it is now, thankfully, under challenge and in retreat. I think this answers **dracoi** ’s point too. Mind you, I am not saying that a snake derives _no perceptual benefit whatsoever_ from having the relevant sensory organs separated at the ends of its forked tongue. I am just saying that this plays a relatively minor role in the snake’s spatio-olfactory perception compared to the role played by moving its head and tongue about. (And the same applies to the separation of nostrils, ears, and even eyes in other animals with paired organs, including humans.) When people make a big deal about the spatial-sensory role played by the anatomical separation of the organs, yet ignore the role of movement, they are (inadvertently) being quite seriously misleading. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [August 28, 2012, 3:30am UTC](https://boards.straightdope.com/t/would-noses-work-better-if-they-were-spaced-further-apart-like-ears/632752/24 "2012-08-28T03:30:45Z")
> [@njtt](#): > > Mind you, I am not saying that a snake derives _no perceptual benefit whatsoever_ from having the relevant sensory organs separated at the ends of its forked tongue. I am just saying that this plays a relatively minor role in the snake’s spatio-olfactory perception compared to the role played by moving its head and tongue about. (And the same applies to the separation of nostrils, ears, and even eyes in other animals with paired organs, including humans.) When people make a big deal about the spatial-sensory role played by the anatomical separation of the organs, yet ignore the role of movement, they are (inadvertently) being quite seriously misleading. Do you have any cites for the separation to play a relatively minor role compared to head movement for both vision and hearing? My understanding is that it is the combination of both factors. For example, there is a fairly significant minority of people who cannot watch 3D movies for too long without experiencing physical discomfort, including nausea, because of the sensory they get from receiving 3D information from the separation of the eyes, but not from turning their heads and other clues. You have to keep in mind that as you turn your head, the separation effect remains and is integrated into the process. Not only that, but the various senses complement each other in order to [establish spatial perceptions](http://www.ncbi.nlm.nih.gov/pubmed/11894093). > [@](#): > > Auditory spatial perception is strongly affected by visual cues. For example, if auditory and visual stimuli are presented synchronously but from different positions, the auditory event is mislocated towards the locus of the visual stimulus-the ventriloquism effect. This ‘visual capture’ also occurs in motion perception in which a static auditory stimulus appears to move with the visual moving object. We investigated how the human perceptual system coordinates complementary inputs from auditory and visual senses. Here we show that an auditory aftereffect occurs from adaptation to visual motion in depth. After a few minutes of viewing a square moving in depth, a steady sound was perceived as changing loudness in the opposite direction. Adaptation to a combination of auditory and visual stimuli changing in a compatible direction increased the aftereffect and the effect of visual adaptation almost disappeared when the directions were opposite. On the other hand, listening to a sound changing in intensity did not affect the visual changing-size aftereffect. The results provide psychophysical evidence that, for processing of motion in depth, the auditory system responds to both auditory changing intensity and visual motion in depth. Coming back to the question of separation of sensors, there is some information, such as high speed movement, where you cannot turn your head fast enough to compensate for lack of stereo viewing. For audio spacial perception, there seem to be many factors, including changes in pitch, the difference between the sound being transmitted through the head vs. coming directly. It’s my understanding that the audio spacial perception process is far too complex to be as definitive as you are in claiming one of the factors to be “minor.” ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [August 28, 2012, 6:17am UTC](https://boards.straightdope.com/t/would-noses-work-better-if-they-were-spaced-further-apart-like-ears/632752/25 "2012-08-28T06:17:37Z")
> [@Der\_Trihs](#): > > The stereo part probably doesn’t help; but having your nostrils right over your mouth makes it more likely you’ll get a whiff of anything dangerous before you absentmindedly gobble it down. Also other evolutionary advantages: - short, direct route to the lungs. If nostrils were spread out, you would need small tubes connecting each of them to the lungs. Hard to do in an already crowded skull. - location near the mouth allows sharing the throat between the breathing and the eating systems. Less space needed in the neck. - built-in redundancy: nostrils close together mean that both lungs can be supplied from either nostril (handy when one is congested). And being near the mouth means that if both are congested, humans can still survive breathing through their mouth. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [August 28, 2012, 12:28pm UTC](https://boards.straightdope.com/t/would-noses-work-better-if-they-were-spaced-further-apart-like-ears/632752/26 "2012-08-28T12:28:27Z")
It strikes me that odors are continual (over multiple seconds at least), wheras sounds can be one-time only or discontinuous things. Which would imply that it’s always possible to move the scent organ around to get directional info on smells, but for sounds that might not be an option. Also, in the real world, wind affects scent a lot, so most of the time the direction of any scent farther than a few feet away is just ‘upwind’. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [August 29, 2012, 1:53am UTC](https://boards.straightdope.com/t/would-noses-work-better-if-they-were-spaced-further-apart-like-ears/632752/27 "2012-08-29T01:53:54Z")
There was a study at Stanford that showed why we need 2 nostrils - read it here > **[Why we evolved two nostrils (hint: it's all about domination)](https://gizmodo.com/why-we-evolved-two-nostrils-hint-its-all-about-domina-5880616)** > > There are sound evolutionary reasons why we have two eyes and two ears. By why do we have two nostrils? Researchers at Stanford University have the answer - after doing a study that revealed the weird reason why we don't have one big hole in our... It has to do with the two nostrils switching roles - one lets in air slower and the other faster - they switch roles throughout the day . The faster one absorbs the highly diffusive smells and the slower ones absorbs the slow diffusing smells thus giving us a complete spectrum of the smells. If this is the only purpose of 2 nostrils - spacing them apart seems to add no value. [Previous page](https://boards.straightdope.com/t/would-noses-work-better-if-they-were-spaced-further-apart-like-ears/632752.md?page=1)