We analyzed over 23 000 hours of auditory exposure data in a cohort study of 27 typically-developing fetuses and 24 preterm infants. Extrauterine exposures for fetuses were captured by having pregnant women wear 24-hour audio recording devices. For preterm infants, recording devices were placed in the infant\'s crib. Multilevel linear regressions were conducted to test for group differences and effects of infant sex, maternal education, and mother\' occupation. A linear mixed-effects model was used to test for an effect of speaker gender.
Fetuses were exposed to an estimated 2.6 ± 1.8 hours/day of nearby, predominantly female language, nearly 5 times greater than 32 ± 12 minutes/day estimated for preterm infants (P < .001). Preterm infants had greater daily exposure to electronic sounds (5.1 ± 2.5 vs 1.3 ± 0.6 hours; P < .001) and noise (4.4 ± 2.1 vs 2.9 ± 2.8 hours; P < .05), with 4.7 ± 3.9 hours/day of silence. Language and extrauterine sound exposure for fetuses showed a marked day/night cyclical pattern, with low exposure during nighttime hours, but preterm infants\' exposures showed significantly less change across the 24-hour cycle (P < .001). Maternal occupation requiring frequent communication predicted greater language exposure (P < .05).
Our findings provide the first comparison of preterm infant auditory exposures to typically-developing fetuses. Some preterm infants may incur deficits of over 150 hours of language exposure over the preterm period. Given known effects of prenatal/preterm language exposure on neurobehavioral outcomes, this magnitude of deficit is alarming.
方法:我们分析了27例发育正常的胎儿和24例早产儿的23,000小时的听觉暴露数据。通过让孕妇佩戴24小时录音设备来捕获胎儿的宫外暴露。对于早产儿,记录设备被放置在婴儿的婴儿床。进行了多水平线性回归以检验婴儿性别的群体差异和影响,母亲教育,和母亲的职业。使用线性混合效应模型来测试说话者性别的影响。
结果:胎儿暴露于附近的估计2.6±1.8小时/天,主要是女性语言,早产儿估计为32±12分钟/天的近五倍(p<0.001)。早产儿每天对电子声音的暴露量更大(5.1±2.5vs.1.3±0.6小时;p<0.001)和噪声(4.4±2.1vs.2.9±2.8小时;p<0.05),4.7±3.9小时/天的沉默。胎儿的语言和宫外音暴露显示出明显的昼夜周期性模式,夜间暴露量低,但早产儿暴露在24小时周期内的变化明显较小(p<0.001)。需要频繁交流的产妇职业预示着更多的语言暴露(p<0.05)。
结论:我们的发现首次比较了早产儿对发育正常胎儿的听觉暴露。一些早产儿在早产期间可能会出现超过150小时的语言暴露缺陷。鉴于已知的产前/早产语言暴露对神经行为结果的影响,这种规模的赤字令人震惊。