Karlsson K K, Harris J R, Svartengren M
Department of Audiology, Karolinska Institute, Huddinge University Hospital, Sweden.
Ear Hear. 1997 Apr;18(2):114-20. doi: 10.1097/00003446-199704000-00003.
The purpose of this study is to present descriptive results from an audiometric examination of a male twin sample, compare the values with normative databases, and explore whether there are age differences in genetic and environmental contributions to variation in hearing.
Audiometric and questionnaire data were collected on a subsample of male twins who were identified through the population-based Swedish Twin Registry. Hearing examinations were completed for a total of 557 intact pairs, comprised of 250 identical (monozygotic [MZ] pairs and 307 fraternal (dizygotic [DZ] pairs aged 36 to 80 yr. A scale measuring hearing in the high-tone ranges was constructed by calculating the mean for the hearing threshold values obtained for both ears combined at 3000, 4000, 6000, and 8000 Hz for air conduction.
To assess whether the twin values are representative of genera hearing function, the hearing thresholds were compared with values from two normative databases. Results suggest that these twin data provide a valid representation of hearing function in a cross-section of the Swedish male population, aged 35 and older. The mean values for hearing ability decreased across age, and variation increased. Twin similarity, estimated across four age groups using intraclass correlations, decreased from 0.716 to 0.516 for the MZ pairs and increased from 0.131 to 0.279 for the DZ pairs. These results suggest that variation in hearing ability in the high ranges is due to genetic and environmental factors and that environmental effects become more important with age.
These data reflect typical age-related deterioration in hearing ability accompanied by greater individual differences in hearing function with age. Across all ages, genetic and environmental effects are important sources of variation in hearing. However, preliminary analyses suggest that the relative influence of environment increases with age. These environmental effects are of the nonshared type that are not associated with shared family environments but rather are explained by unique exposures.
本研究旨在呈现对男性双胞胎样本进行听力测试的描述性结果，将这些值与标准数据库进行比较，并探讨在听力变异的遗传和环境贡献方面是否存在年龄差异。
通过基于人群的瑞典双胞胎登记处识别出的男性双胞胎子样本收集了听力测试和问卷调查数据。对总共557对完整双胞胎进行了听力检查，其中包括250对同卵双胞胎（单卵双胞胎[MZ]）和307对异卵双胞胎（双卵双胞胎[DZ]），年龄在36至80岁之间。通过计算在3000、4000、6000和8000赫兹气导时双耳听力阈值的平均值，构建了一个测量高音范围听力的量表。
为了评估双胞胎的值是否代表一般听力功能，将听力阈值与两个标准数据库的值进行了比较。结果表明，这些双胞胎数据有效地代表了35岁及以上瑞典男性人群横断面的听力功能。听力能力的平均值随年龄下降，变异增加。使用组内相关系数在四个年龄组中估计的双胞胎相似性，MZ对从0.716降至0.516，DZ对从0.131增至0.279。这些结果表明，高音范围内听力能力的变异是由遗传和环境因素引起的，并且环境影响随着年龄增长变得更加重要。
这些数据反映了与年龄相关的典型听力能力下降，同时随着年龄增长听力功能的个体差异更大。在所有年龄段，遗传和环境影响都是听力变异的重要来源。然而，初步分析表明，环境的相对影响随着年龄增长而增加。这些环境影响属于非共享类型，与共享家庭环境无关，而是由独特的暴露所解释。
