2 sentences for 话筒 (huà​tǒng — handset)

1. 她用手捂住了电话的话筒。

   tā yòng shǒu wǔ​zhù le diàn​huà de huà​tǒng.

   She covered the mouthpiece of the phone with her hand.

   Source: Tatoeba

2. 他轻轻地放下了话筒，结束了通话。

   tā qīng​qīng de fàng​xià le huà​tǒng, jié​shù le tōng​huà.

   He gently put down the receiver and ended the call.

   Source: Dong Chinese Dictionary