Effects of noise on health are well-documented such a irritability, hearing loss and mental disorders. Effects of noise on safety are commonly perceived that the machine operator and helpers or other crew members cannot communicate with each other, so the reduction of noise will also contribute towards occupational safety goals. However a noticeable enough level of sound must still be available that can serve as auditory warning and peripheral sensation.

The noise observation from 7.5 meters of moving vehicle comes from the Agreement Concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, Equipment and Parts which can be Fitted and/or be Used on Wheeled Vehicles and the Conditions for Reciprocal Recognition of Approvals Granted on the Basis of these Prescriptions. The same noise standard 85 dB(A) at a distance of 25 feet was adopted in Pakistan when Euro-2 was adopted circa. 2009-2012 thru S.R.O 72 (KE)/2009. This is for a moving vehicle and IMHO the test is not strong enough because it helps a by-stander but does not cater to the people who have to work inside or in close proximity to the vehicle. It also does not cater to the passengers of the vehicles who face the multiple jeopardy of of not only that vehicle they’re occupying, but the combined noise of all the vehicles surrounding them. There is a concept of idle engine noise in European standards but hasn’t been adopted in Pakistan AFAIK.