Normal voice heard from 1 meter, intensity of sound reaching ear is -
Normal conversation produces 60-70 dB. Whisper 20-30 dB. Mechanical damage at 150-160 dB REF. PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 22nd EDITION. PAGE NO - 688
20 dB
40 dB
60 dB
80 dB
Environment and health