This should be challenged in court as an infringement of Section 7 of the Charter of Rights and Freedom: the right to life, liberty and security of the person. There is the right to security of the person, which consists of rights to privacy of the body and its health.
In Chaoulli v Quebec (AG) (2005), the majority of Supreme Court justices declared Quebec's ban on private health care to breach security of the person, since delays in medical treatment can result in serious physical pain, or even death.
I would see a strong argument that prohibiting suppressors in Canada negatively affects one's health (mainly hearing loss).