They both offer great sound insulation, as well as various sounds designed to induce sleep, and a built-in ventilation system.

它们都提供了很好的隔音效果，以及各种旨在引导睡眠的声音，以及内置的通风系统。

Indeed, the chevrons were so effective  at reducing noise than Boeing estimated hundreds of pounds of sound insulation could  be removed from the aircraft.

事实上，人字形在降低噪音方面的效果如此之好， 波音公司估计可以从飞机上去除数百磅的隔音材料。