Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
| Type of area |
Day time
(7am-10pm) |
Night time
(10pm-7am) |
| Residential area | 55 dB | 45 dB |
| Commercial-residential area | 60 dB | 50 dB |
| Commercial area | 65 dB | 55 dB |
| Residential-industrial area | 70 dB | 60 dB |
| Industrial zone | 75 dB | 65 dB |
Note: (Leq (30min) dB (A) = level equivalent to 30 minutes in duration measured in A weight channel (based on sensitivity of human ear) and its unit is dB.
