[Automated hearing threshold estimation in newborns using extrapolated DPOAE input/output functions].
OBJECTIVE
A new method for automatically assessing hearing loss by means of extrapolated DPOAE I/O-functions was applied for the first time in newborns.


METHODS
DPOAE I/O-functions were recorded in 118 ears of 93 newborns (mean age 3 days) at 12 frequencies between 1 and 8 kHz. L(2) was varied between 20 and 65 dB SPL with L(1)=0.4L(2)+39 and f(2)/f(1)=1.2. Auditory thresholds were constructed using the estimated DPOAE threshold level from extrapolated DPOAE I/O-functions. Follow-up measurements were conducted in 15 ears 4 weeks later.


RESULTS
The first measurement revealed a high-frequency hearing loss. The second measurement showed normal hearing function. This fact and the decrease of DPOAE level in the frequency range of the hearing loss, while keeping the compressive shape of the DPOAE I/O-functions, indicate that transitory sound conduction disturbance may be due to amniotic fluid.


CONCLUSIONS
The method fulfils the essential criteria for screening newborn hearing. It is fast and easy to handle, and measurement and data analysis are performed automatically. Preliminary results suggest that the new method is able to differentiate between transitory middle-ear dysfunction and persisting cochlear disorders. Due to its better diagnostic capabilities in comparison to TEOAE, DPOAE, and FAEP, this method may provide a new instrument with which to make a fast evaluation of hearing function in children.
Janssen
T
T
Hals-Nasen-Ohren-Klinik, Technischen Universität München, Klinik rechts der Isar, Munich. t.janssen@lrz.tum.de
Klein
A
A
Gehr
D D
DD
D000161:Acoustic Stimulation; D001300:Audiometry, Evoked Response; D001309:Auditory Threshold / Q000502:physiology*; D003051:Cochlea / Q000503:physiopathology; D003936:Diagnosis, Computer-Assisted; D005260:Female; D005500:Follow-Up Studies; D006311:Hearing Disorders / Q000151:congenital* / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D010898:Pitch Perception / Q000502:physiology; D011237:Predictive Value of Tests; D011785:Quality Assurance, Health Care; D012815:Signal Processing, Computer-Assisted