People differ in their sensitivity to noise due to variety reasons including age. If you have to shout to communicate with a normally hearing person at a distance of about 3 feet, the background noise is potentially harmful. When the noise becomes harmful you can feel it.
- Ears start paining
- Ears starts ringing
- Causes temporary hearing loss
- Palpitation, anxiety etc.,
Typically all noise above 85 Db are harmful. The higher Db level, the lower time that a person should expose himself to. If the Db level is 80, up to 8 hours exposure may not bring in permanent damage. However, if the Db level is above 110, exposure to even half an hour could bring in permanent damage.