Technically, snoring is defined as any resonant noise from the respiratory tract that emerges during sleep.
Biologically, snoring refers to a vibration in the airway connecting the nose and the mouth; a vibration that can emerge through the mouth, the nose, or (as some non-snorers are painfully aware), it can emerge through both!
As you can sense, the more narrow the airway, generally speaking, the more intense the vibration; and ultimately, the louder the snore.
You may also be wondering why snoring only seems to emerge at night; after all, people literally use their airway every moment of their life; so why is snoring a nocturnal dilemma?
The answer to this is found in looking at the tissues within the airway. This tissue is very soft, and at night becomes relaxed; it's similar to how some muscles, like biceps, become relaxed at night since the body does not require them.
As the throat (and its subsequent tissue) relaxes during sleep, the wind tunnel/airway becomes narrower and hence, snoring occurs.
Why Do Some People Snore Louder than Others?
This, too, is the reason why some people snore louder than others; and why the actual tone and pitch of one snorer may be rather different than another.
The actual snoring sound that emerges is dependant upon the force of wind that is being pushed through the (narrowed) airway. As you can envision, the more potent the force of wind (i.e. the faster the speed of the wind), the louder the snoring.
This is also why even babies can snore; but it's often not considered snoring in the conventional sense, because an infant's force of wind through their wind tunnel is so mild, that it can easily be ignored (though this can lead to complications; infant snoring can often be a symptom for a breathing and/or respiration problem, including allergy).
However, while snoring affects people of both genders and of all ages, it typically does afflict more men than women. Overall, men's necks tend to be larger than women's necks; and thus there may be more fleshy tissue in there just waiting to combine with air flow and cause snoring.
Another reason is that women produce the hormone called Progesterone, which is considered by some medical experts to be an aid in reducing or preventing snoring. In fact, there are some anti-snoring treatments that involve Progesterone therapy for snoring men.
