The result of these types of discipline is that you become a better listener in all aspects of your waking hours. While driving and listening to the radio or tapes, keep an analytical ear open. In conversation, be still and really listen to what is being said so that you can get the entire message the first time. If you have difficulty with that, learn to ask questions. Remember that good relative pitch is the most important trait to develop.
Retention is always a mental discipline.
Start practicing it now. On The Net Parts 1-4 Listening Vs.