Can I recommend that you not suppress a gun that is intended to be used for self defence.
I know your reasoning is probably that a loud report indoors could damage your hearing, but silencers or more correctly 'sound moderators' are a tool linked with 'offensive' use in that their user intends to capitalise on the element of surprise, and for this reason they are associated with hit men.
The use of a silencer could influence the decision to prosecute and may also influence a jury.
If worried about heading use a load that is not going to go throught the sound barrier.