她得了重感冒，开始失声。

She had a bad cold and started to ___lose ___her ___voice.

在演讲过程中，他因为紧张而失声了。

During his presentation, he ___lost ___his ___voice from nervousness.

在音乐会上大喊大叫之后，我完全失声了。

After shouting at the concert, I completely ___lost ___my ___voice.