2 sentences

1. 他们的电话被警方窃听了。

   tā​men de diàn​huà bèi jǐng​fāng qiè​tīng le.

   Their phone was wiretapped by the police.

   Source: Dong Chinese Dictionary

2. 他躲在门后窃听他们的谈话。

   tā duǒ zài mén hòu qiè​tīng tā​men de tán​huà.

   He hid behind the door to eavesdrop on their conversation.

   Source: Dong Chinese Dictionary