voice可数吗?

　　例句：

　　She sighed, then continued in a soft, calm voice.

　　她叹了口气，然后继续用温柔、平静的声音说下去。

　　It was just an ordinary voice,but he sang in tune.

　　他声音很一般，但唱得都在调子上。

　　Miriam's voice was strangely calm。

　　米里亚姆的声音异乎寻常地平静。