This is the first comprehensive account of prolonged hearing loss and its impact on a language that was once spoken fluently. Although it is currently assumed that hearing loss results in speech deterioration, it is shown that language loss occurs when speakers remain deaf for a long time. The reader is introduced to a significant deaf population -- postlingually deafened Yoruba speakers who have been deaf for more than twenty years and who have no access to hearing aids or speech therapy. After becoming deaf, they continue to speak Yoruba from memory and "hear" visually through lip...