We overheard them arguing.

我们碰巧听到他们吵嘴。

《牛津词典》

I overheard two doctors discussing my case.

我无意中听到两个医生在讨论我的病例。

《柯林斯英汉双解大词典》

I overheard him say he was going to France.

我偶然听见他说他要去法国。

《牛津词典》

" I smiled, and she added, "It's a good thing no one overheard me.

NPR: Excerpt: 'Hungry for Paris'

He overheard me talking about Steve in relation to my UC Santa Barbara entrepreneurship class.

FORBES: Steve Jobs: 6 Tried-And-True Business Tips

The incident was overheard by another guest at the lodgings, who called the police.

BBC: Oxford grooming: Girl Three's story