The nose of a human person has the ability to detect more than a trillion odors different, however, between them our body odor and our breath cannot be found, something that could put us in trouble on more than one occasion. Several theories could provide an answer to this problem, according to Gizmodo.
The first one explains that perhaps get used to our own stench, which causes that we can no longer detect it, just as it happens with the smell of our house. According to this hypothesis, acclimatization of our nose our scent allows us to capture other unknown odors that could warn us of a possible danger.
Instead, another of the theories holds that our receptors catch other people’s breath Because the air that is expelled when speaking is different from the one that is let out when exhaling, since the movement of the tongue while we dialogue causes the smells from the back of our mouth to come out of it. An action that we cannot perform at the same time.
But, following this logic, we could indeed know how our breath smells when we speak, something that the last hypothesis explains: we cannot smell it because we cannot completely release the air from our lungs and inhale at the same time.
When a person speaks, his interlocutor breathes that air almost at the same time, therefore, if we are the ones who are speaking we cannot perceive it because it is not possible to inhale at the same time as we exhale, so before we can detect the smell of our breath, it has already dissipated.