The first is simple: focus on the speed and volume levels of one's voice.

要注意说话的语速和音量。

You know, that's always a, a very inoffensive way of taking the volume level down, getting information, cooling people off.

你知道，这始终是一种非常无害的方式，可以降低音量、获取信息、让人们冷静下来。

When the crowd hits the chorus, the volume levels on the shaky smartphone video blow their limit, exploding into a delirious roar of noise.

当人群齐声合唱时，这段晃动的智能手机视频的音量水平达到了极限，爆发出一阵极度亢奋的声音。

We used a sound level meter to detect the outside volume level and then looked at how I adjusted my volume on my iPhone in turn.

我们用音量测试器来检测外界的声音，接着看我如何调整 iPhone的音量大小。