infrasonics

例句：

1. 1. The aircraft was traveling at an infrasonic speed.
   飞机以超音速飞行。
2. 2. The sound of the explosion was so loud that it could be heard over the infrasonic roar.
   爆炸声如此巨大，以至于它能够被超音速的咆哮声所掩盖。
3. 3. Infrasonic waves are used to detect underwater objects.
   超音速波用于探测水下物体。