Sentence:  And sure enough she had settled down at once, so that in less than two months it seemed to Stephen that Miss Puddleton must always have been at Morton, must always have been sitting at the large walnut table, must always have been saying in that dry, <WSD>toneless</WSD> voice with the Oxford accent: ‘You've forgotten something, Stephen,' ... 
Meaning of the word marked with <WSD> tags:  Lacking tone or expression.