I am currently working on my pronunciation materials. People say that if you can pronounce correctly, you can listen just as well…Half true. It really depends on what you listen to and to what degree you would like to understand what material. So it is always necessary that you make out why pronunciation is important.
From a perspective of someone who teaches the TOEFL, it IS important. So long as you need a score of not less than 23 in the speaking section, it is important.
Why? Because you want to make your speech sound like a native to impress raters? Not at all.
As a matter of fact, if you don’t pronounce correctly (or differently from the way it should sound), your speech is always too slow to develop your main ideas. You cannot touch on all the important ideas within the designated time (45 or 60 seconds).
I personally find it fascinating to hear non-native English because it sounds different and I regard it a sign of their identity. I just like it. I sometimes even wish I could display a Japanese accent in my speech. However, I have also realized (through my own experiment on the actual test!) that I cannot make it, because I cannot pick up speed. I am sure that most of the learners wish they could speak faster and thus better. I also know that their pronunciation is not up to par.
The most important part of the pronunciation exercise is to forget about your own mother tongue. So long as your native language affects your English, you are not learning well. (I repeat. There is nothing wrong with it in your daily communication, but that does not help you get the TOEFL score.) My advice is that you look at each one of the phonetic signs and learn how to pronounce them. If you have done it, the next step is to keep it in mind every time you speak or read aloud English.
Just like other aspects of learning English, learning is a matter of consciousness.