In Canada there are basically two streams to do this, becoming an Audiologist or a Hearing Instrument Practitioner (HIP).
The profession in BC is regulated by the College of Speech and Hearing Health Professionals of BC (CSHHPBC) and minimum level to practice is a Clinical Masters in Audiology. The three English speaking programs to obtain one are at UBC in Vancouver, Dehousie in Halifax and UWO in London, these programs typically take 3 years to complete. Entrance into these programs typically requires an undergraduate degree and some prerequisits meaning your total time of study is actually usually 7 years, though well worth it in by biased opinion.
As mentioned, you also have the option of becoming an HIP which would still allow you to dispense hearing aids although there would be some limitations (e.g. prescription rights, pediatric fitting and some third party payments like workman’s compensation for example). As I understand it there are also 3 English programs in the country. Grant MacEwan College (Edmonton) is your closest and also has a distance program. George Brown College (Toronto) and Conistoga (Kitchner) are also choices. Training is typically between 2-3 years.
Hope that helps!