Martin Lloyd Jones wisely says in his classic, Spiritual Depression, "Most of your unhappiness in life is due to the fact that you are listening to yourself instead of talking to yourself.”
As someone who, while working, exercising, and moving from one place to another, listens to 5-7 sermons a week, I can appreciate the power of words.
The voice in your head greatly impacts the way you live your life. We become like those we listen to, whether a critical parent or a tenderhearted pastor. Their habits, tone, and content direct our own hearts and actions. We will hear that voice when we walk, pray, write, and solve problems. The Spirit sometimes takes on those godly voices. Satan speaks through the complaining and argumentative around us. It is thus no surprise to us, having experienced this dynamic in our own hearts, that we then see our children becoming like us, particularly in their temperament and speech. Thanksgiving, patience, shortness, and quickness of speech are all possible fruits of our hours and years of pouring words as seeds into their hearts. The voice in their head shall guide their (and our) lives.