Rytzner B, Rytzner C
Scand Audiol. 1981;10(4):213-6. doi: 10.3109/01050398109076183.
Tone screening was performed in 14391 schoolchildren at three different age-levels, 7, 10, 13 years in grades 1, 4 and 7, and was carried out in 1977, 1978 and 1979. A 4 kHz dip greater than 20 dB was found in 331 (2.3%) of the children; 241 (1.7%) were boys and 98 (0.6%) were girls. The 4 kHz dip was unilateral in 230 (1.6%) and bilateral in 109 children (0.7%). The number of children with the 4 kHz dip increased with age. At the 13-year level it was found in 125 (4.7%) boys and 37 (1.5%) girls. The magnitude of the dip increased with age both in frequency range and intensity. At the 13-year level two and more frequencies were affected in 27 (0.5%) and hearing thresholds of 40 dB and worse were found in 47 (0.9%) of the children. Causes of noise could be established in 210 (63%) of 331 children. Most important noise causes were in the following order: motor vehicles, including tractors, fire-arms and crackers. In a small number, loud music could have been the cause of the 4 kHz dip. A hearing conservation program against noise has been instituted for children, parents, teachers and school nurses. Further studies will show if this program is effective.
对14391名不同年龄段（7岁、10岁、13岁，分别为一年级、四年级和七年级）的学童进行了音调筛查，筛查于1977年、1978年和1979年进行。发现331名儿童（2.3%）存在大于20分贝的4千赫凹陷；其中男孩241名（1.7%），女孩98名（0.6%）。4千赫凹陷单侧出现的有230名儿童（1.6%），双侧出现的有109名儿童（0.7%）。有4千赫凹陷的儿童数量随年龄增加。在13岁年龄段，发现125名男孩（4.7%）和37名女孩（1.5%）存在该凹陷。凹陷的幅度在频率范围和强度上均随年龄增加。在13岁年龄段，27名儿童（0.5%）有两个及以上频率受到影响，47名儿童（0.9%）的听力阈值达到40分贝及更差。在331名儿童中的210名（63%）身上可以确定噪音成因。最重要的噪音成因按以下顺序排列：机动车辆，包括拖拉机、火器和鞭炮。少数情况下，大声播放的音乐可能是4千赫凹陷的成因。已经为儿童、家长、教师和学校护士制定了一项针对噪音的听力保护计划。进一步的研究将表明该计划是否有效。
