Shahnaz Navid
School of Audiology and Speech Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
J Am Acad Audiol. 2008 May;19(5):419-29. doi: 10.3766/jaaa.19.5.4.
Wideband reflectance (WBR) provides important information about middle ear function and can explain variations in how the middle ear receives, absorbs, and transmits sound energy across a wide range of frequencies. However, as of yet, few normative studies have been published to guide clinicians in the practical applications of WBR. WBR has been measured more extensively in well babies than in neonatal intensive care unit (NICU) babies, who have significantly higher incidence of otitis media with effusion (OME).
The goal of this study was to explore the characteristics of the middle ear while using energy reflectance (ER) and normalized admittance in NICU babies who passed automated auditory brainstem response (AABR) and evoked otoacoustic emission (EOAE) hearing screening criteria and to compare these characteristics to patterns in normal hearing adults. This study was done to identify ways to implement WBR so it could improve hearing assessment in newborns.
Thirty-one neonatal intensive care unit (NICU) babies with an average gestational age (GA) of 37.8 weeks (range: 32-51 weeks) and 56 adults with normal hearing between the ages of 18 and 32 years served as subjects in this study. NICU babies and adults were tested using multifrequency tympanometry (MFT) and WBR.
WBR can be obtained on what appears to be a majority of NICU babies without other abnormal findings. Maximum absorption of the incident energy appears to occur at a narrower range of frequencies in normal NICU babies in comparison to normal hearing adults. This range becomes even narrower in NICU babies who fail EOAE screening. In most NICU babies who failed EOAE screening, ER values were closer to 1 (most incident energy is reflected) at a frequency below 3000 Hz. The measurements of normalized acoustic admittance may also be very useful and may supplement ER and tympanometric data in evaluating middle ear status.
宽带反射率（WBR）提供了有关中耳功能的重要信息，并且可以解释中耳在很宽的频率范围内接收、吸收和传输声能方式的差异。然而，截至目前，很少有规范性研究发表，以指导临床医生在WBR的实际应用中。与中耳积液（OME）发病率显著更高的新生儿重症监护病房（NICU）的婴儿相比，WBR在健康婴儿中得到了更广泛的测量。
本研究的目的是探讨通过自动听性脑干反应（AABR）和诱发耳声发射（EOAE）听力筛查标准的NICU婴儿使用能量反射率（ER）和归一化导纳时的中耳特征，并将这些特征与正常听力成年人的模式进行比较。进行这项研究是为了确定实施WBR的方法，以便改善新生儿的听力评估。
本研究以31名平均胎龄（GA）为37.8周（范围：32 - 51周）的新生儿重症监护病房（NICU）婴儿和56名年龄在18至32岁之间听力正常的成年人为受试者。NICU婴儿和成年人使用多频鼓室图（MFT）和WBR进行测试。
在大多数没有其他异常发现的NICU婴儿中似乎可以获得WBR。与正常听力成年人相比，正常NICU婴儿中入射能量的最大吸收似乎发生在更窄的频率范围内。在EOAE筛查未通过的NICU婴儿中，这个范围变得更窄。在大多数EOAE筛查未通过的NICU婴儿中，在低于3000 Hz的频率下，ER值更接近1（大部分入射能量被反射）。归一化声导纳的测量也可能非常有用，并且在评估中耳状态时可能补充ER和鼓室图数据。
