They amplified their sound.是什么意思？

They amplified their sound.

他们提高了嗓门。

they

pron. 他/她/它们，人们，大家，政府，当局，她们；

例句
The storms had abated by the time they rounded Cape Horn.
他们绕过合恩角时，暴风雨已经减弱。

amplified

v. 放大，扩大( amplify的过去式和过去分词 )，增强，详述；

例句
The music was amplified with microphones...
音乐声通过麦克风被放大。

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

sound

n. 声音，声响，音调，声调，声波，嘈杂声；vi. 响，发声，听起来，好像，回响，[音乐]乐器等被奏响；vt. 使出声，使发声，清楚地发出，宣布，发表，颂扬；adj. 健全的，合理的，完好的，无损的，明智的；adv. 彻底地，充分地；

例句
Their sleep is regularly disturbed by the sound of gunfire as criminal gangs settle their nightly accounts.
他们经常被黑帮每晚火拼的枪声所吵醒。