Get Rid of Your Accent: General American: American Accent Training Manual (Unabridged‪)‬

This audiobook is a leading accent-reduction toolkit with practical exercises to master a general American accent. It contains explanations on how to form correct English sounds. The audiobook provides extensive practice with words, sentences, and funny verses. 

This audiobook is compact and easy to use with its 44 short lessons, each devoted to a single phoneme. 

For each phoneme, there is a list of words containing the target sound, a list of sentences, a few verses, a few tongue-twisters, and some articulation exercises. The more you listen, the better your pronunciation becomes, because you get a feeling for how words should be pronounced. After the listening phase, try to repeat as many times as you can: again, practice makes perfect! A bit every day is much better than a lot only once a week, so try to be consistent and your efforts will be repaid. You'll soon see that the right pronunciation will come perfectly naturally to you. 

The pluses are that you can study pronunciation whenever and wherever you are (during your commuting time, for example). Another useful feature is that the verses and tongue-twisters are a bit silly and very amusing, so you won't get bored!