And whereas clever engineering can sharply reduce an aircraft's radar signature (as Russia has shown by redesigning Iran's Shahed kamikaze drones with stealthier composites), propelling hardware through the air generates sound.

尽管巧妙的工程设计可以大幅降低飞机的雷达信号（正如俄罗斯通过使用隐身性更强的复合材料重新设计伊朗的沙希德神风特攻队无人机所展示的那样），但在空中推进硬件会产生声音。