Both of them were tested by the high frequency audiometry(HFA), and the results were analysed. Results: The average threshold of HFA in study group(27.97dBSPL) was higher than that of control group(19.17dBSPL).

• 结果 :实验组延伸高频听阈平均值为 2 7.；97dBSPL；对照组为 19