The pitchlessness of thought

When I speak to myself, in the quietitude of my own thoughts, my thoughts lack pitch or timbre; even though when I speak aloud, my voice has these properties. I think that is part of why I have always been disturbed by the sound of my own voice, having pitch, having timbre, it sounds so alien to how I normally speak to myself, in pitchlessness, in timbrelessness.

And yet, when I sing to myself in my own private thoughts, my thoughts then have at least some pitch, although they still struggle to attain timbre. Maybe, my struggles in conception, are related to my own limits of musical ability? (Then again, if only I had practiced as much as I might have, my musical ability might be much, much, greater than it is now.)