Does laser-assisted palatoplasty reduce snoring index or snoring sound level?

Laser-assisted palatoplasty (LPP) reduces non-apnoeic snoring according to both subjective and objective assessment [Drinnan et al. Clin Otolaryngol 1999; 24: 335-338], but it is unclear whether LPP affects the total number of snores, the volume of the individual snores, or a combination of the two. From forty-one habitual snorers recruited from a snoring clinic, twenty completed the protocol of two pre-operative sleep studies, LPP, and a further sleep study 6 months post-operativery. The first pre-operative study was used for acclimatisation and screening for obstructive sleep apnoea. Changes between the second pre-operative and post-operative studies were attributed to LPP. Periods of wakefulness and obvious artefacts were excluded, then snores (phasic sound peaks >40 dBA recorded by a room microphone) during each 6-hour sleep study were identified by automated analysis. We examined changes in four indices of snoring severity following LPP: snores per hour of sleep (the snoring index); mean amplitude of snores; snores >45 dBA per hour, snores >50 dBA per hour. All indices of snoring severity were significantly reduced (t-test, all p< 0.02). However, the reductions in snores >45 dBA (155 to 62 h-1) and in snores >50 dBA (89 to 25 h-1) were proportionally greater than for total snores (241 to 145 h-1). We conclude that LPP reduces the perceived severity of snoring by reducing both the snoring index and the volume of the remaining snores.