More technically speaking - the Silent Partner senses the amplitude and frequency of the disturbing sound wave and broadcasts in real-time, a sound wave with an inverted phase. Based on the physics phenomena of destructive interference, the two waves line up, essentially cancelling out each other's sound.
The innovative "subwavelength active noise cancellation" technique enables a more accurate noise reduction around the snoring person which is effective from as close as 20cm (8 inches) away.