title: Infant sleep machines and hazardous sound pressure levels.
abstract: OBJECTIVE
  Infant "sleep machines" (ISMs) produce ambient noise or noise to mask other sounds in an infant's room with the goal of increasing uninterrupted sleep. We suggest that the consistent use of these devices raises concerns for increasing an infant's risk of noise-induced hearing loss. We therefore sought to determine the maximum output levels of these sleep machines.
  
  
  METHODS
  Sound levels of 14 ISMs played at maximum volume were measured at 30, 100, and 200 cm from the machine using correction factors to account for a 6-month-old's ear canal.
  
  
  RESULTS
  Maximum sound levels at 30 cm were >50 A-weighted dB for all devices, which is the current recommended noise limit for infants in hospital nurseries. Three machines produced output levels >85 A-weighted dB, which, if played at these levels for >8 hours, exceeds current occupational limits for accumulated noise exposure in adults and risks noise-induced hearing loss.
  
  
  CONCLUSIONS
  ISMs are capable of producing output sound pressure levels that may be damaging to infant hearing and auditory development. We outline recommendations for safer operation of these machines.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University of Toronto, Toronto, Canada; and.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Hugh
authors.forename: Nikolaus E
authors.initials: NE
authors.lastname: Wolter
authors.forename: Evan J
authors.initials: EJ
authors.lastname: Propst
authors.forename: Karen A
authors.initials: KA
authors.lastname: Gordon
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Cushing
authors.forename: Blake C
authors.initials: BC
authors.lastname: Papsin
mesh_terms: D006801:Humans; D007223:Infant; D015370:Infant Equipment; D011312:Pressure; D012306:Risk; D012890:Sleep; D013016:Sound / Q000009:adverse effects*
keywords: hearing loss, noise induced; infant development; infant equipment; noise; sleep