This thread is interesting!
I mostly dream in silence as far as the actual content of my dream, even as far as people in my life who in the waking world only communicate with me through text, but in my dreams, they are signing fluently. However, when I wake, I sometimes recall music that was somehow playing in the background of my dreams, but not affecting my dreams.
Sometimes in real life I can hear well enough to listen to music, which I enjoy very much, but speech makes no sense to me, and it is rarely exist in my dreams. Sometimes, I dream stressful situation I can hear people talking, I'm struggling to understand them, but I don't think I ever dream that I can understand speech. There's usually no sound in my dreams except the background music that I don't notice until I wake.