This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hearing Loss, Subject name: ENT
[{'content': 'Patient with anotia ideal hearing aid - \nSelect and explain. \nA. Incanal, B. Bone anchored hearing aid, C. Vestibular, D. Transcutaneous', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e.. Bone anchored hearing aid o Anotia ("no ear" ) describes a rare, congenital deformity, that involves the complete absence of the pinna, the outer projected portion of the ear, and narrowing or absence of the ear canal,o A bone-anchored hearing aid is an implantable device that allows the listener to hear by bone conduction without the inconvenience of a traditional bone conduction hearing aid. It\'s more comfortable, and the sound quality\' is better, partly because the device stays in place.o Unlike a middle ear implant, which requires a normally functioning middle ear, this type of hearing aid is typically used by listeners who have conductive or mixed hearing loss. Bone conduction hearing aids have traditionally been used by people bom without ear canals or with small, misshapen ears that can\'t support conventional hearing aids, or by people who have chronic middle ear disease that\'s aggravated by wearing a hearing aid or earmold in the ear canal (for example, people with draining ears).', 'role': 'assistant'}]