Macrae J
National Acoustic Laboratories, Chatswood, New South Wales, Australia.
J Rehabil Res Dev. 1990 Fall;27(4):397-410. doi: 10.1682/jrrd.1990.10.0397.
Four experiments were carried out to investigate the effect on the static pressure seal of earmolds made from currently used impression and earmold materials; the occasional practice of making more than one earmold from an impression; the earmoldmaker buildup of impressions; and the multistage buildup of impressions by the impression taker. Experiment 1 showed that the chance of sealing the ear with earmolds made by the ordinary two-stage technique with only general buildup of the impression was approximately 10 percent and that none of the impression or earmold materials significantly improved the chance of obtaining a seal. Experiment 2 showed that the chance of obtaining a seal with multiple earmolds made from the one impression was zero, or very close to zero. Experiment 3 revealed that the chance of obtaining a seal increased to 55 percent when the earmold was made from an impression which was specially built up by the earmoldmaker. Experiment 4 showed that the chance of sealing the ear with earmolds made from multistage impressions was significantly greater (87.5 percent) than sealing the ear with those made from impressions specially built up by the earmoldmaker.
进行了四项实验，以研究当前使用的印模和耳模材料制成的耳模对静压密封的影响；偶尔从一个印模制作多个耳模的做法；耳模制作人员对印模的加厚处理；以及取模人员对印模进行多阶段加厚处理。实验1表明，采用仅对印模进行一般加厚处理的普通两阶段技术制作的耳模，封堵耳朵的几率约为10%，且没有一种印模或耳模材料能显著提高获得密封的几率。实验2表明，用同一个印模制作多个耳模获得密封的几率为零，或非常接近零。实验3显示，当耳模由耳模制作人员特别加厚处理的印模制成时，获得密封的几率增加到了55%。实验4表明，用多阶段印模制作的耳模封堵耳朵的几率（87.5%）明显高于用耳模制作人员特别加厚处理的印模制作的耳模封堵耳朵的几率。
