title: Do snoring sounds arouse the snorer?
abstract: OBJECTIVE
  Respiratory cycle-related electroencephalographic (EEG) changes (RCREC), especially in delta and sigma frequencies, are thought to reflect subtle, breath-to-breath inspiratory microarousals that are exacerbated in association with increased work of breathing in obstructive sleep apnea (OSA). We wondered whether snoring sounds could create these microarousals, and investigated whether earplugs, anticipated to alter snoring perception, might affect RCREC.
  
  
  METHODS
  Randomized controlled trial.
  
  
  METHODS
  An accredited, academic sleep laboratory.
  
  
  METHODS
  Adults (n = 400) referred for suspected OSA.
  
  
  METHODS
  Subjects were randomly assigned to use earplugs or not during a night of diagnostic polysomnography.
  
  
  RESULTS
  Two hundred three of the participants were randomized to use earplugs. Earplug use was associated with lower RCREC in delta EEG frequencies (0.5-4.5 Hz), although not in other frequencies, after controlling for potential confounds (P = 0.048). This effect of earplug use was larger among men in comparison with women (interaction term P = 0.046), and possibly among nonobese subjects in comparison with obese subjects (P = 0.081). However, the effect of earplug use on delta RCREC did not differ significantly based on apnea severity or snoring prominence as rated by sleep technologists (P > 0.10 for each).
  
  
  CONCLUSIONS
  This randomized controlled trial is the first study to show that perception of snoring sounds, as modulated by earplugs, can influence the cortical EEG during sleep. However, the small magnitude of effect, lack of effect on RCREC in EEG frequencies other than delta, and absence of effect modulation by apnea severity or snoring prominence suggest that perception of snoring is not the main explanation for RCREC.
authors.affiliation: Sleep Disorders Center and Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Naricha
authors.initials: N
authors.lastname: Chirakalwasan
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Ruzicka
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Burns
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Chervin
mesh_terms: D000328:Adult; D004430:Ear Protective Devices; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D020181:Sleep Apnea, Obstructive / Q000150:complications*; D012913:Snoring / Q000150:complications*; D014851:Wakefulness / Q000502:physiology*
keywords: Polysomnography; RCREC; computer-assisted signal processing; earplugs; obstructive sleep apnea; respiratory cycle-related EEG changes; snoring; sound
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