The first point is that the decision will be taken by the panels that are conducting the hearings. The guidance that is being given is to make sure the people who are directly affected and therefore have an interest in the project will be heard. I'm quite sure they will not be mechanistic about this, and if there will be an impact on people a little farther away, they would take that into account.
The other category of people who would be allowed to be heard would be experts whose expertise could add to the knowledge that's relevant for the panel to consider. The important point here is that there should be a relationship between the scope of the hearing and the subjects that are relevant to the people wishing to appear.
To give you an example of that, the Northern Gateway hearing does not include in its scope the issue of global warming and greenhouse gas emissions. Important though those issues are from a society perspective, they're not issues that are directly related to the project in question.