Richards W D, Frank T A, Prout J H
J Acoust Soc Am. 1979 Jan;65(1):257-9. doi: 10.1121/1.382245.
Although the dimensions of the MX-41/AR earphone cushion are specified in ANSI S3.6--1969, nonstandard MX--41/AR cushions are still found on some audiometers. Variations in the diameter of the cushion's center hole are shown to affect the coupler calibration of the earphone and also hearing threshold measurements at high audiometric frequencies.
尽管MX - 41/AR耳机垫的尺寸在ANSI S3.6 - 1969中有规定，但在一些听力计上仍能发现非标准的MX - 41/AR垫子。结果显示，垫子中心孔直径的变化会影响耳机的耦合器校准，还会影响高听力测试频率下的听力阈值测量。
