We report the case of a patient, Dr O, who has impaired auditory comprehension, but intact written comprehension. His ability to repeat words that he cannot comprehend, along with good performance on lexical decision suggest that Dr O has an impairment of the mappings between lexical and semantic representations; a word meaning deafness. Dr O's ability to understand heard words depends on their imageability and their length, such that he is poor at comprehending words which are short and abstract. This is interpreted in terms of lexical and semantic distinctiveness.