Sentence:  ‘A—hem!' cried the same voice; and that, not in the tone of an ordinary clearing of the throat, but in a kind of bellow, which woke up all the echoes in the neighbourhood, and was prolonged to an extent which must have made the unseen <WSD>bellower</WSD> quite black in the face. 
Meaning of the word marked with <WSD> tags:  One who bellows.