Meditation is the best tool for neutralizing the voice in the head. It's a muzzle for the ego. Being mindful is an innate but underused ability we all have, the act of being aware without judging. When you repeatedly go through the cycle of trying to focus on your breath, losing that focus, and noticing and returning to the practice, you are literally building your mindfulness muscle the same way dumbbell curls build your biceps. As this mind-muscle develops, you start being way more aware of thoughts, emotions, and sensations as what they really are: squirts of chemicals & hormones that enter, peak and then fade completely back to the nothingness of which they arose. In other words, mindfulness provides space between impulse and action, so you're not a slave to whatever pops into your head. You are not your thoughts. You are the awareness of them.