You can’t produce what you can’t audiate, or listen in your mind. Ear training is essential to music training.
There are, arguably, four ways to do ear training, in increasing difficulty:
- Passively listening to music (probably age dependent).
- Practicing without an instrument (usually, websites and apps)
- Practicing with an instrument.
- Actively trying to conceptualize within a theoretical framework what’s happening in the music: transcribing.
Arguably, three and four are the most transferable approaches when one is a musician. Vocabulary doesn’t happen in a vacuum - and that’s kind of my gripe with producing music from software (see note on the benefits of interpretation).