Wichman H, McIntyre M, Accomazzo E
Aviat Space Environ Med. 1979 Sep;50(9):898-900.
Ten low-time pilots (less than 150 h) who did not normally use earplugs flew three flights each in Cessna-152 training planes. The flight routines were all the same, lasting about 45 minutes. Each pilot flew one flight while adapting to earplugs, another flight with earplugs, and a third flight without earplugs. Pilot's breathing rate was the measure of autonomic arousal. A baseline rate was measured before each flight and in-flight scores were expressed as changes from baseline. Half the pilots flew their flights in the order, with-with-without earplugs and half flew in the order without-with-with. Results showed a mean increase in breathing rate above preflight baseline of 30% without earplugs and an increase of only 21% with earplugs (data taken from second flight with earplugs) for a significant savings of 9% (p less than 0.025, Wilcoxsen matched-pairs signed-ranks test, one tailed).
十名飞行时间较短（少于150小时）且通常不使用耳塞的飞行员，每人驾驶Cessna - 152型训练飞机进行三次飞行。飞行程序完全相同，持续约45分钟。每位飞行员在适应耳塞的情况下飞行一次，佩戴耳塞飞行一次，不佩戴耳塞飞行一次。飞行员的呼吸频率作为自主唤醒的指标。每次飞行前测量基线频率，飞行中的得分表示为相对于基线的变化。一半的飞行员按佩戴-佩戴-不佩戴耳塞的顺序飞行，另一半按不佩戴-佩戴-佩戴的顺序飞行。结果显示，不佩戴耳塞时，呼吸频率平均比飞行前基线增加30%，佩戴耳塞时（数据取自第二次佩戴耳塞的飞行）仅增加21%，显著降低了9%（p小于0.025，Wilcoxsen配对符号秩检验，单尾）。
