It was my bad, i hit the wrong reply.
To answer your question, Because you dont have to if your still pledging with your right hand. I sometimes say the pledge and sometimes i dont just so i can hear others say it out loud. Understand it is not disrespectful if you dont say it as long as you have your right hand over your heart.
You can't hear and speak at the same time? I ask this because I sure can hear and speak at the same time. Whenever I recite the pledge with others, I hear them. Are you telling me you can't?