Listening is important, yes, especially for pronunciation. Learners need a great deal of exposure to map the various sounds of the language, be it their 1st or 2nd language. Any given sound has a miminum of three variants: at the start of a word, at the end of a word, and in the middle of a word.
Add to that the different environments that a sound can sit in. The sound [ae] in 'apple', for example, is slightly different from the [ae] in 'hat' and in 'plant'. The sounds around it change its perception, slightly, but nevertheless, native speakers know this intuitively as they have had enough exposure to map the variants.
The same holds true for all language. Any given sound has more than one perception. Knowledge of that is called 'nativeness'.
Listening Skills 
Linear Mode
