Long-term stability between click-evoked otoacoustic emissions and distortion product otoacoustic emissions in guinea pigs: A comparison.
This study examines the long-term stability of otoacoustic emissions (OAEs), and we selected click-evoked otoacoustic emissions (CEOAEs) and distortion product otoacoustic emissions (DPOAEs) from several types of OAEs. We then compared these methods for the long-term monitoring of inner ear functions. Over a period of 8 weeks, we measured CEOAEs and DPOAEs in guinea pigs (n = 8) every week and analyzed the changes in the total echo power of CEOAE, the echo power of frequency bands of CEOAE and the DPOAE level (f2/f1 = 1.2). We considered as 'stable' parameters those that showed small changes or of which the p value was close to 1.0. Good p values of CEOAEs were obtained over the 2- to 3-kHz range; better p values of DPOAEs were obtained over the 2- to 8-kHz range. Thus, DPOAEs afforded the extended frequency information achievable with CEOAEs. According to our results, DPOAEs were superior to CEOAEs as parameters of long-term stability because they showed fewer changes in level at each frequency.
Hoshino
M
M
Department of Otolaryngology, Nagoya University School of Medicine, Nagoya, Japan. mhoshino@tsuru.med.nagoya-u.ac.jp
Ueda
H
H
Nakata
S
S
D000161:Acoustic Stimulation / Q000379:methods*; D000818:Animals; D003051:Cochlea / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000502:physiology; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D013997:Time Factors