I talk, but I do not speak my mind
He is reading a script..so not his own thoughts
I hear words, but I do not listen to thoughts
Double meaning possibly. For one..goes with first line..with how it is a script. 2nd..the idea that thoughts in plays are often spoken aloud for the audience
When I wake, all see me
Being on stage
When I sleep, all hear me
Hearing his thoughts/dreams (or, a more simple answer, his snoring..exaggerating it so audience can hear)
Many heads are on my shoulders
Many faced - different characters he portrays
Many hands are at my feet
Stage hands? This one I'm not as sure about
The strongest steel cannot break my visage
Staying in character (visage=facial expressions. So it is stating that nothing could prevent him from breaking his facial expressions)
But the softest whisper can destroy me
2 possible meanings
1) The whisper is him breaking character or forgetting lines (this one is what I think it means)
2) Whispers, in plays, are usually used when someone is plotting something
The quietest whimper can be heard.
Another 2 meaning
1) Breaking character again
2) In plays, quiet things are made loud so the audience can hear it (this is what I believe it means)