Question: who did the demon voice in the exorcist
[{'answer': 'Carlotta Mercedes Agnes McCambridge', 'provenance': [{'wikipedia_id': '533847', 'title': 'Mercedes McCambridge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 35, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '533847', 'title': 'Mercedes McCambridge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 418, 'bleu_score': 0.9492177523638841, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12741517100946700179}, 'section': 'Section::::Abstract.'}]}]