Planners and governmental officials like to have a “budget” that can be used for approving or denying projects.
Unfortunately, the human being does not act as an adding
machine for sound, where you can get to “too much.” Each
person hears the components of the environment and will
know where each individual sound is coming from. In the
case of internal combustion engines, it is possible to not
know whether the engine is a distant car, airplane, or something else. As the sound source gets closer, an identification
can often be made. The budget approach has been successfully used for hearing loss in workplaces. In the case of community projects, the equivalent level (Leq
) or the day-night Aweighted equivalent level (DNL), used in transportation
projects, has a disconnect with the levels observed by the
people impacted by the sounds from the project. One concern is the statement about the percentage of highly annoyed
residents. There seems to be a tacit assumption that some
percentage of residents can be permitted to be highly
annoyed by a project. What if this small percentage turns out
to be those who are physically disposed to some disease, such
as motion sickness? Are they to be “thrown under the bus”
because they are highly annoyed about it? The percentage
which was used for aircraft in the 1970s was 15% highly
annoyed. Has anyone ever talked to these people about why
they are highly annoyed? If those people have to move out of
their homes because of the noise, will the project or the government compensate them? Probably not. It will be: “Too bad
for you,” which will just make them more upset