deaden|deadened|deadening

这些耳塞可以减弱噪音。

These earplugs help to ___deaden the noise.

连续加班让他感觉精力被耗尽了。

The constant overtime work ___deadened his energy.

长时间的工作会议让人感到乏味，气氛变得沉闷无趣。

The long work meeting had a ___deadening effect on everyone's mood.