Snoring has a simple definition: During sleep, the muscles of the tongue and throat relax, narrowing the airway, and the vibration of air through this constricted passage creates hoarse or harsh sounds.

Much more complicated is the effect snoring has on relationships, and how to cure it. Snoring is a "big relationship divider," said Laura Berman, a relationship and sex therapist in Chicago. She said snoring creates frustration and resentment on both sides: the snorers, who can't help it, and those suffering next to them.

Complications include "low energy from not getting enough revitalising sleep, making you grumpy, less communicative and with less sexual energy," she said.

Beyond a regular nudge in the ribs to make the snorer roll over and stop snoring, potential remedies can include anything from earplugs for the sleep-deprived to surgery for the snorer.

Nearly half of adults snore occasionally, and a quarter are habitual snorers, according to the American Academy of Otolaryngology, whose physician members specialise in ear, nose and throat care. Snoring increases with age and weight, and happens most often when the guilty party is asleep on his or her back.