CPCB's Technical Guidelines/SOPs
In WHO noise quality guidelines, values are summarized with regard to specific environments and effects. For each environment and situation, the guideline values take into consideration the identified health effects and are set, based on the lowest levels of noise that affect health (critical health effect). Guideline values typically correspond to the lowest effect level for general populations, such as those for indoor speech intelligibility. Noise guideline values are for the onset of health effects from noise exposures.
| Specific Environment | Time Base (hours) | Standard limits as per WHO guidelines | |
|---|---|---|---|
| LAeq [dB] | LAmax, fast [dB] | ||
| Outdoor living area | 16 | 50 - 55 | - |
| Dwelling, indoors, Inside bedrooms | 16 8 |
35 30 |
- 45 |
| Outside bedrooms | 8 | 45 | 60 |
| School class rooms and pre-schools, indoors | During class | 35 | - |
| Pre-school bedrooms, indoors | Sleeping time | 30 | 45 |
| School, playground outdoor | During play | 55 | - |
| Hospital, ward rooms, indoors | 8 16 |
30 30 |
40 - |
| Hospitals, treatment rooms, indoors | - | As low as possible | - |
| Industrial, commercial, shopping and traffic areas, indoors and outdoors | 24 | 70 | 110 |
| Ceremonies, festivals and entertainment events | 4 | 100 | 110 |
| Public addresses, indoors and outdoors | 1 | 85 | 110 |
| Music through headphones/earphones | 1 | 85 (under headphones, adapted to free-field values) | 110 |
| Impulse sounds from toys, fireworks and firearms | - | - | 120-140 (peak sound pressure (not LAmax, fast), measured 100 mm from the ear) |
| Outdoors in parkland and conservation areas | - | Existing quiet outdoor areas should b e preserved and the ratio of intruding noise to natural background sound should be kept low | - |
