First of all, hi!
I have been around for some time, reading and learning from the discussions on this wonderful site, and this is my first post. I have been learning the piano for half a year now. loving it and lamenting that i did not start it earlier (I am 29 now). But, its never too late, right?
So, I wanted to know how you heard a piano piece in your head? I had never wondered about that, but recently I noticed that when I heard a piece (a melodic line, chords, anything on a piano), I heard it as if I was singing it with my voice (like "ta tata", or "la la la", whatever), of course, with the correct pitch, and dynamics, etc, but just as if I was singing it.
I have been trying since then to "shut myself up" and listen to a real piano sound in my head. It has not been easy, I can only sustain it for short periods of time, before I start hearing my voice again, and I only hear it faintly, but it has gotten better with time, and it allows me to catch glimpses of really hearing a piano, with its sound and polyphony. But I have to focus really hard
That got me wondering how other people heard that.

ok, I reread this and a doctor could easily diagnose me as "borderline insane" or potentially schizophrenic, hehe, so I hope at least you guys and gals kind of understand what I am trying to say.
Thanks and I hope to hear from you.