trail off什么意思？

Shorty screamed, then let his voice trail off in a gale of wild laughter.肖提尖叫着, 把声音拖长,发出一阵狂笑.The audience began to trail off when the speaker continued for over an hour.当讲演者讲了1个多小时后,听众就开始闲谈....

trail off的音标：trail off的英式发音音标为：[treil ɔf]trail off的美式发音音标为：[trel ɔf]...