话筒 

Pinyin: huàtǒng 
Meaning：Transmitter; mike 
Sentence：对着话筒说清楚些。Speak clearly into the microphone.

More: 

话： 

Pinyin: huà 
Meaning: Language; speech; words
Radical: 讠
Stokes: 8
Traditional: 話
Common words/Phrase:
话题 [huàtí] 【topic; subject】
话剧 [huàjù] 【stage play; modern drama】
话音 [huàyīn] 【one's voice in speech】
说话 [shuōhuà] 【utterance】

筒： 

Pinyin: tǒng
Meaning: Tube; cylinder
Radical: 竹
Stokes: 12
Traditional: 筒
Common words/Phrase:
筒子 [tǒngzi] 【pony roll】 
筒子楼 [tǒngzilóu] 【tube-shaped apartment】
筒瓦 [tǒngwǎ] 【pantile】
筒式 [tǒngshì] 【barrel type】