Effect of sleep stages on synchronized spontaneous otoacoustic emissions in pre-term neonates.
OBJECTIVE
In infants, auditory tests are mainly performed during sleep, since they spend most of their time asleep, and because quiet is required for the duration of the recording session to obtain a precise and reliable response. The aim of this study was to investigate the effect of sleep stages on synchronized spontaneous otoacoustic emissions (sSOAEs) in pre-term neonates at the age where the sleep states begin to be well established and auditory screening can be performed in a neonatology unit before discharge.


METHODS
Synchronized SOAEs were repeatedly recorded during a polygraphic sleep recording using the Otodynamic ILO88 system in 10 pre-term neonates at 36 weeks post-conception.


RESULTS
Variations of sSOAE peak numbers occurred in each subject during the recording session. There was no clear relation between sSOAE peak number fluctuations and the different sleep stages.


CONCLUSIONS
The sSOAE variations appeared to be closely related to experimental conditions, i.e. the mean background noise level. sSOAEs with the highest amplitude were always recorded; however, those with the smallest amplitude were the first to disappear from the recordings with higher background noise.
Morlet
T
T
Kresge Hearing Research Laboratory of the South, Louisiana State University Health Sciences Center, 2020 Gravier Street, Suite A, New Orleans, LA 70112-2234, USA.
Ferber-Viart
C
C
de Bellescize
J
J
Badinand
N
N
Duclaux
R
R
D000161:Acoustic Stimulation; D005260:Female; D006311:Hearing Disorders / Q000175:diagnosis; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D015997:Neonatal Screening; D017084:Otoacoustic Emissions, Spontaneous; D017286:Polysomnography; D012894:Sleep Stages / Q000502:physiology*