来自 tone,音调，-less,无，没有。

1. "What shall we do?" Milton said again in a toneless voice.

“我们该怎么办？”米尔顿又用平板而单调的声音问道。

来自柯林斯例句

2. What shall we do? Milton said again in a toneless voice.

“我们该怎么办？”米尔顿又用平板而单调的声音问道。

来自辞典例句

3. Though her voice was toneless, it plead more loudly than words.

她的声音尽管听起来很平谈, 但比大声的要求更加诚恳.

来自飘（部分）

4. His voice was flat and toneless.

他的语气很平淡,听不出任何感**彩.

来自互联网

5. His voice was flat, toneless.

他的语气很平淡, 听不出任何感**彩.

来自互联网