I can just barely read standard musical notation but it’s far from fluent. I’m wondering if, with enough practice you can look at sheet music that you have never heard or seen before and sound it out in your head before ever touching your instrument?
I’m REALLY BAD at sight reading but no when I do it, I don’t hear the notes in my head. It’s more like touch typing, transferring the sheet music to keystrokes on the piano. People I know who are better at it and know more theory than I do can read a score and audeate (= like “visualize” but for sound) the music. I think the key to that is ear training rather than sight reading per se. I have a reasonably good ear for single pitches but no ear training. Maybe someday.
Same for me for strings. Shapes on the page mean finger positions, only a vague idea what it would sound like until I play it.