a person who swims as deep as they can under water without using breathing equipment

As the freediver descends, pressure increases, with the same effect on the eardrum as in flying. 随着自由潜水员的下潜，压力增加，对鼓膜的影响和飞行时是一样的。

Some free-divers, who swim without a snorkel or scuba gear, can hold their breath for more than 10 minutes. 一些不带通气管或水肺的自由潜水者可以屏住呼吸超过10分钟。