Dr KK Aggarwal
Padma Shri Awardee
As per guidelines, the permissible noise levels in residential areas is 45 dB in night time and 55 dB in day time. Permissible noise limits in Silence zones are 50 dB in daytime (6am to 10 pm) and 40 dB in night time (10 pm to 6am). Silence zone is referred as areas up to 100 meters around such premises as hospitals, educational institutions and courts.
In the last three years, I have checked noise levels in CMEs organized by various bodies and found them to between 60 and 100 dB. For a proper attention span, the noise levels should be below 50 dB.
If a mike is used in a conference hall, the background noise level is more than 50 dB. Noise from other rooms, hallway noises, or noise within the hall itself such as conversation of the audience, noise from AC/fans, phones ringing, turning paper, etc. adds to the decibels. Background noise interferes with auditory communication and adversely affects speech perception and speech recognition. It also affects attention and memory.
One can tolerate exposure to 80 dB for up to 8 hours in a day; 85 dB for 4 hours; 90 dB for 2 hours; 95 dB for one hour; 100 dB for 30 minutes; 105 dB for 15 min and 110 dB for less than a minute without adequate sound protection.
People shout at each other in anger, but speak softly when expressing love. The distance remains the same, it’s the tone of the speech, which changes.
Exposure to noise beyond permissible levels is a health hazard. Noise shifts the body to sympathetic mode and takes us away from conscious-based decisions. Hence, we should make an effort to speak softly to minimize the ambient noise levels.
Vedic literature has described four gradations or levels of sound: Para (background noise of nature, no spoken sound), pashyanti (observed sound or perceived in mind), madhyama (audible sound), and vaikhari (articulated sound or spoken words). We should speak in Pashyanti and madhyama.
A national workshop Noise and Health was organized on Sunday at Hotel Le Meridian for Safe Sound initiative of IMA as part of the National Initiative for Safe Sound (NISS). The workshop was inaugurated by IMA National President Dr Ravi Wankhedkar. Dr John Panicker was the National Co-ordinator. Through this initiative, IMA has entrusted itself with the responsibility of achieving noise pollution free India.
According to new estimates released by WHO on the occasion of World Hearing Day on March 3, around 900 million people could suffer from disabling hearing loss by 2050. Exposure to loud sounds through personal audio devices and in entertainment venues and workplaces is a major factor contributing to the rising prevalence of hearing loss.
All of us are now used to mikes in class rooms or lecture halls or DJ music.
Instead, ask the audience “Am I audible?” If you are audible without mike, then don’t use a mike. When I spoke in the IMA NISS workshop, I did so without using a mike.