In musical terms this is called audiation - the ability to imagine sound. From my experience, this can be acquired indirectly over time through regular vocal and musical practice (e.g., singing in a local choir or practicing an instrument). You can write music with or without it, or using both: sometimes you have a specific sound in your head that you want to materialize, other times you're experimenting with your instrument and discovering new sounds that you could not have imagined.

I don't know how much of this applies to visual artists, but there's probably some overlap there.

> the ability to imagine sound

This is a real, normal thing?? I can hear snippets of music, usually orchestral or opera, as vividly as if they were actually playing, but all I'm listening to is the white noise of a fan, and I'm just remembering them from before. When I was young, it was often a radio announcer because we listened to the radio in the car a lot. I always thought this was very bizarre and was not supposed to happen to normal people.

I have no issue imagining sounds, with any detail I want. It’s images that are hard (but then more abstract things like graphs are easy).

Do you actually hear the music in the fan noise or do you hear/imagine it in your mind? The first one is to consider carefully as it happens on LSD and in psychosis - maybe also strong synaesthesia or HPPD - , the second one is normal.

Sounds like audial daydreaming, where white noise would be perfect for triggering almost any memory of music depending on the fluctuations of frequencies. Staring at the static on an old TV does the same thing visually if you look at it and relax your focus.

There is a technique of drawing where it's more like a printer. You progress down line by line only drawing what is needed in that row. when you get to the bottom your done.

This style of drawing doesn't have that feedback loop of looking at what you already have on the paper. Everything is planned in advance and you can't go back to change stuff.