Hunter Lisa L, Keefe Douglas H, Feeney M Patrick, Fitzpatrick Denis F, Lin Li
Cincinnati Children's Hospital Medical Center, USA.
Boys Town National Research Hospital, USA.
Hear Res. 2016 Oct;340:3-14. doi: 10.1016/j.heares.2015.12.014. Epub 2015 Dec 19.
The goals of this study were to measure normal characteristics of ambient and tympanometric wideband acoustic reflectance, which was parameterized by absorbance and group delay, in newborns cared for in well-baby and Neonatal Intensive Care Unit (NICU) nurseries, and to characterize the normal development of reflectance over the first year after birth in a group of infants with clinically normal hearing status followed longitudinally from birth to one year of age.
Infants were recruited from a well-baby and NICU nursery, passed newborn otoacoustic emissions (OAE) and automated auditory brainstem response (ABR) tests as well as follow-up diagnostic ABR and audiometry. They were tested longitudinally for up to one year using a wideband middle ear acoustic test battery consisting of tympanometry and ambient-pressure tests. Results were analyzed for ambient reflectance across frequency and tympanometric reflectance across frequency and pressure.
Wideband absorbance and group delay showed large effects of age in the first 6 months. Immature absorbance and group delay patterns were apparent in the low frequencies at birth and one month, but changed substantially to a more adult-like pattern by age 6 months for both ambient and tympanometric variables. Area and length of the ear canal estimated acoustically increased up to age 1 year. Effects of race (African American and others compared to Caucasian) were found in combination with age effects. Mean and confidence intervals are provided for use as a normative longitudinal database for newborns and infants up to one year of age, for both well-baby and NICU infants.
本研究的目的是测量在健康婴儿护理室和新生儿重症监护病房（NICU）中接受护理的新生儿的环境和鼓室声导抗宽带声反射的正常特征，该特征通过吸光度和群延迟进行参数化，并描述一组听力临床正常的婴儿从出生到一岁纵向随访期间出生后第一年反射率的正常发育情况。
从健康婴儿护理室和NICU招募婴儿，他们通过了新生儿耳声发射（OAE）和自动听性脑干反应（ABR）测试以及后续诊断性ABR和听力测定。使用由鼓室声导抗测试和环境压力测试组成的宽带中耳声学测试组合对他们进行长达一年的纵向测试。分析了频率范围内的环境反射率以及频率和压力范围内的鼓室声导抗反射率的结果。
宽带吸光度和群延迟在出生后的前6个月显示出年龄的显著影响。出生时和1个月时，低频处的吸光度和群延迟模式不成熟，但到6个月大时，环境和鼓室声导抗变量的模式都显著变化为更接近成人的模式。通过声学估计的耳道面积和长度在1岁前增加。发现种族（非裔美国人和其他种族与白种人相比）的影响与年龄影响相结合。提供了均值和置信区间，用作健康婴儿和NICU婴儿出生至1岁的新生儿和婴儿的规范性纵向数据库。
