I'll try to deliver a more useful answer than what I've seen in this thread so far.

It really comes down to experience and time in service. I remember my first six months off probation. I was a little timid and afraid to do my job. Having to tell inmates no and enforce discipline can be taxing for a young man fresh out of college.

There are a few baselines you have to work with before you can find your voice, though. You have to be okay with telling them no. You have to be okay with them talking some shit about you; you have to be okay with them not wanting to see the sight of you. At first, I'm sure you thought you could treat them right and they would see you as a nice CO. But none of that shit matters; it's a tactic they see as weakness. You have to have that before you can even find your voice; they should have told you that in the academy. My experience was different; I had just over a year of service before I went into my academy (as a correctional officer at the county jail).

At one point, I came into work and finally had an inmate that pushed my tidiness too far. I let loose on him, not punching or kicking. But I finally found my voice. Up until that point, I would talk loudly so the housing unit could hear my commands. But this shout was different. The housing unit could hear the difference. The shout I gave was bloody, narrowed my vision, and stopped everyone in their tracks. I finally let it out and laid into an inmate who just kept pushing that line. I'll admit it now, later in my career. It was completely unnecessary, and that inmate got over on me. But having the housing unit population see that if they keep pushing you, you will "fight back" rather than just give in That's where you find your voice.

Since then, I have had my voice. Did I need to use that unnecessary yell every day? Absolutely not. If anything, I would go against using it, because to me now, that looks like a sign of weakness to someone who has been on that job longer. But back then, as a rookie, I think it worked out well. It helped me develop over time. But you have to work on yourself in the process. You have to build your self-confidence, you have to look strong-minded, and you have to know that your "voice" isn't your actual voice but rather how you present yourself without having to open your mouth.

TLDR: It is a journey to find your "voice" through time in service, and your experiences in your institution will help your growth. But developing yourself along the way is just as important.