"trail away" in Chinese (Simplified)
逐渐消失（声音/话语）
Definition
逐渐变得更小声或更弱，最终消失，尤其是指说话或发声时。
Usage Notes (Chinese (Simplified))
常用于描述说话声音或其他声音渐渐消失，多见于故事叙述中。不能用于具体物体，只用于描述声音、语气等。
Examples
His voice began to trail away as he got nervous.
他紧张时，声音开始**逐渐消失**。
The music slowly trailed away at the end of the song.
歌曲结束时，音乐**逐渐消失**。
Her laughter trailed away when she saw the teacher.
她看到老师时，笑声**逐渐消失**。
He started to say something, but his words just trailed away into silence.
他想说些什么，但话语**逐渐消失**在寂静中。
The speaker's voice trailed away as the microphone stopped working.
当麦克风坏了，演讲者的声音就**逐渐消失**了。
I could hear his footsteps trail away down the hallway until everything was quiet.
我能听见他的脚步声**逐渐消失**在走廊尽头，一切变得寂静。