This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General, Subject name: ENT
[{'content': 'Tone decay test is done for: \nSelect and explain. \nA. Cochlear deafness, B. Neural deafness, C. Middle ear problem, D. Otosclerosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (b) Neural deafness(Ref. Anirban Biswas, 5th ed. 56)Tone decay is a function of nerve fatigue.If the nerves are fatigued the patient stops hearing a sound given to him continuously before the completion of 1 minute.A tone decay of more than 30dB is suggestive of retrocochlear or neural deafness', 'role': 'assistant'}]