title: Frequency shifts with age in click-evoked otoacoustic emissions of preterm infants.
abstract: A previous study [Brienesse et al. (1997). Pediatr. Res. 42, 478-483] demonstrated a positive shift with increasing postmenstrual age (PMA) in the frequencies of synchronized spontaneous otoacoustic emissions (SSOAEs) in preterm infants. We used a mixed model approach to describe a shift with PMA in the spectra of click-evoked otoacoustic emissions (CEOAEs) measured in a group of 22 preterm infants. The rate in shift in CEOAE spectral components was found to be frequency dependent, with a mean estimate of 10 Hz/week for frequencies around 2 kHz and 30 Hz/week for frequencies around 4.25 kHz. This rate decreased with increasing PMA. Because SSOAEs are often part of the CEOAE response, a comparison was made between the shifts in SSOAEs and CEOAEs in a sub-group of 16 preterm infants. The results indicate that the shifts found for both types of OAE are similar, which supports a common mechanism for this change in OAE-characteristic. At present it is not clear to what extent developmental processes in the cochlea and the middle ear can account for these frequency shifts in the spectra of CEOAEs and SSOAEs during the preterm period.
authors.affiliation: Department of Otorhinolaryngology and Head and Neck Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands. s.w.j.ubbink@med.umcg.nl
authors.forename: Sander W J
authors.initials: SW
authors.lastname: Ubbink
authors.forename: Pim
authors.initials: P
authors.lastname: van Dijk
authors.forename: Emile
authors.initials: E
authors.lastname: de Kleine
authors.forename: Patrick
authors.initials: P
authors.lastname: Brienesse
authors.forename: Michelene N
authors.initials: MN
authors.lastname: Chenault
authors.forename: Frans E S
authors.initials: FE
authors.lastname: Tan
authors.forename: Lucien J C
authors.initials: LJ
authors.lastname: Anteunis
mesh_terms: D000161:Acoustic Stimulation; D001306:Auditory Pathways / Q000254:growth & development*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008954:Models, Biological; D017084:Otoacoustic Emissions, Spontaneous; D012815:Signal Processing, Computer-Assisted; D013018:Sound Spectrography