Mike, what exactly happens to her when she hears a loud noise? I would think that in the rare case that she had to discharge a gun to save her life the side effects would be worth it. Seems like synesthesia is more of a trigger of seeing colors, etc. when hearing certain noises, sounds, etc. I don't know anything about synesthesia, but I found this: My wife doesn't want to carry a gun and when with me she knows I will protect her. At home she knows how to access a gun if needed and she knows how to use them. One can be nurturing and still take appropriate actions to stay safe so they can nurture. It's just a matter if they want to or not, no matter what you want. I know plenty of people who gladly choose not to protect themselves and I just accept it and hope they are never in that situation. Layers of security and her being aware will go a long way. A knife, pepper spray, etc. could enhance her ability to fight back if needed, but even I would hate to depend on those items unless that's all I had.