This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Air, Light, Sound, Housing, Radiation, Waste Disposal, Subject name: Social & Preventive Medicine
What is the suggested level of noise that people can tolerate without damage to their hearing? 
Select and explain. 
A. 60 dB, B. 85 dB, C. 110 dB, D. 120 dB
B: 85 dB
Answer: B: 85 dB 
Explanation: Daily maximum tolerable sound level to human ear : 85-90 dB. Human ear is sensitive to sound frequency: 20-20,000 Hz. Auditory fatigue appears in: 90 dB. Sound level above which tympanic membrane rupture: 150 - 160 dB. Permanent hearing loss : >100 dB. Hospital ward, permissible level of sound : 22-35 dB. Normal conversation: 60-70 dB.