Differences between Pressurized and Non-Pressurized Transient-Evoked Otoacoustic Emissions in Neonatal Subjects

Introduction: Recently, Interacoustics presented a new otoacoustic
emission protocol where the probe pressurizes the
ear cavity, thus eliminates the risk of non-assessment (REFER
outcome) due to a negative middle ear pressure. This study
evaluated the characteristics and the performance of this
new protocol on a newborn well-baby population. Methods:
One hundred sixty-three newborns (age 2.7 ± 1.1 days) for a
total of 294 ears were assessed randomly. Transiently evoked
otoacoustic responses were acquired by the Titan device (Interacoustics),
using the default and a pressurized TEOAE protocol.
The data were analyzed in terms of signal to noise ratios
(S/Ns) at 5 frequencies, namely, 0.87, 1.94, 2.96, 3.97, and
4.97 kHz. To assess any possible gestational age (GE) effects
on the TEOAE variables, the responses were subdivided in 4
different age subgroups. Results: There were no significant
differences between the left and right ear TEOAE responses,
for age (in days), GE (in weeks), weight (in grams), and S/N at
all 5 frequencies. Considering the pooled 294 ears, paired t
tests between the default and the pressurized TEOAE data
showed significant differences across all 5 frequencies (p <0.01). The pressurized protocol generated TEOAE responses
presenting larger S/Ns, and a positive additive effect of approximately
2.31 dB was observed at all tested frequencies.
There were no significant GE effects on the pressurized TEOAE
responses. In terms of performance, both protocols performed
equally (same number of PASSes). Conclusion: The
pressurized TEOAE protocol generates responses with higher
S/Ns which might be useful in borderline cases where the
middle ear status might cause a REFER screening outcome.