Eli5: Why are peoples’ own noises and smells usually dialed down, such as not being affected by their own snoring and not noticing their body odor?



Why does the brain seems to dial down things that we produce; even the obnoxious snoring or noises made while sleeping don’t affect us? Similarly, people don’t usually get annoyed by their own talking or yelling to themselves.

In: Other

You have to live with yourself all the time. If you were constantly focusing on how you smelled, talked, acted, etc, etc, you would quickly find your own existence barely tolerable.

You get used to the sounds and smells you make and your brain starts filtering them out, because paying attention to your surroundings is more important for survival.

The most basic signs of “intelligence” is the ability to respond to your environment. You poke the thing, it reacts

The next step on the intelligence ladder is ignoring stimuli. You poke the thing often enough, it will stop reacting when you poke it.

Your brain is constantly fed an amazing amount of information, so to save on processing power it chooses to ignore certain things. You can hear your own heart beat/ feel yourself breathing/ feel your clothes/ smell yourself. But, because these things are always there, your mind chooses to ignore it in favor of processing other stuff.

So, why can’t people smell themselves? They can, their brain just chooses to ignore it.

Novelty makes us pay attention to things. After a while we block it out. Think of your house smell vs smelling someone else’s house. The same with sound, people that have lived all their lives in noisy places tend not to pay attention to them.

You don’t sense *things*, you sense *changes* in things. When you get constant input, your senses stop responding to it.

That’s why jumping into a pool feels cold, then an hour later you don’t even notice the water temperature at all.

This happens because of something called [sensory/neural adaptation](https://en.m.wikipedia.org/wiki/Neural_adaptation). Like the other comments have said, we respond to changes in stimuli. If something happens continuously, eventually your neurons reduce their sensitivity to that stimulus.

For example, after a while you don’t notice the sound of a fan if it’s been on for a long time or the feel of the clothes you’re wearing.

This [link](https://users.pfw.edu/abbott/120/adaptation.html) lists a few other examples related to sight, hearing, touch, smell, and hand-eye coordination.

for the same reason you don’t notice your nose in front of your face or if you stare into a mirror for a long time your brain gets bored and starts doing wonky things. our brain likes novelty and we’ve spent millions of years evolving so our brain is efficient at noticing things that are different. with things that are constant they are not as important to our survival so our brain chooses to ignore these things, even tho it is still receiving input from them, to save energy. if we spent all our energy realizing that our heart is beating at every second of the day we’d have less energy to fight off that mountain lion that wants to eat your face.

It’s the same reason you don’t notice the feeling of socks against your feet all day. Its a familiar, unimportant detail you experience frequently. You brain ignores it and puts that effort into focus on other things.

My boyfriend actually *does* wake himself up from his own loud snoring. It’s hilarious most of the time. It’s totally possible to affect yourself with snoring or BO, but I’d imagine that over time, you’d get used to whatever your status quo is and would just tune it out, like you do the noise the fridge is making all the time.