Abstract:
CONCLUSION: High frequency immittance measurements demonstrate promise in clarifying middle ear status for neonates but age- and gender-specific norms should be consulted. OBJECTIVE: To describe high frequency immittance measurements using a 1000 Hz probe tone for a sample of 278 neonatal ears (0-4 weeks of age) in order to compile normative
tympanometric and acoustic reflex criteria. SUBJECTS AND METHODS: Assessment of
neonatal ears included 1000 Hz probe tone immittance measurements (tympanograms
and ipsilateral acoustic reflexes), and distortion product oto-acoustic emission (DPOAE) screening. Results were compared and normative values were compiled for immittance measures in ears controlled for normal middle ear functioning (n=250). RESULTS: Comparison of immittance results to OAE screening outcome provides estimates of
sensitivity and specificity for middle ear fluid with tympanometry of 57% and 95%, and
57% and 90% for acoustic reflex presence, and 58% and 87% for combined
tympanogram and acoustic reflex results, respectively. Normative data indicate that static
peak admittance values differ significantly across gender and age with the 5th percentile
cut-off value for the entire sample at 1.4 mmho. The 90% range of tympanic peak
pressure normative values increases with increasing age from 140 daPa for neonates 1
week of age to 210 daPa for neonates 2-4 weeks of age. Acoustic reflexes were elicited at
93±9 dB with a 90% normality range of 80-105 dB.
