If you complain the city will make them move the generators or reduce the noise anyways, regardless of if they have a permit.
Even Noise Exemption permits are very easy to revoke if you have more than one resident complain. It only took two complaints in our neighborhood to shut down some generators in a similar situation.
In our case we had put up with the noise for about a week before we started talking to the builder who told us to fuck off, then we filed complaints.
http://www.calgary.ca/CSPS/ABS/Pages...on-Permit.aspx
Can a permit be revoked?
The City of Calgary can revoke a noise exemption permit if the applicant has not taken sufficient measures to minimize the noise, or if conditions stated within the permit have been violated
What information do I need before applying for a permit?
When applying for a permit, you are required to provide:
•Ways you will reduce the noise and stop any disturbance to the area residents.
Basically you can make them reduce the noise to prevent disturbances