Listening again and again is a fantastic way to learn the different sounds in English. We learn to tell the difference in sounds by listening to the same thing many times.
Words are made of individual sounds. Many people focus only on these individual sounds. Pay attention to longer groups of words each time. Some words and syllables make almost no sound. Words with more than one syllable have more emphasis on one of the syllables. Different words in a sentence have more emphasis. There is a speed and rhythm to the way people talk. Too fast or too slow confuses other speakers of the language. There is a pitch or song to the way people talk. English is not a monotone language.
Do this everyday for 10 minutes.
The podcast from January 25, 2010 (link to mp3) starts like this:
"Tonight. (pause) Building consensus. (short pause) Reconstruction is on the agenda at an international summit in Montreal."
The announcer joins 'building' and 'consensus'. It sounds like 'buildingconsensus'. 'Is on' sounds like 'izon'. She also joins all the words in the third sentence. 'On', 'an' and 'in' have very little emphasis and are said very quickly.
What do you have trouble with? Pay attention to the way you say R's. If you have difficulty with 'Reconstruction' and 'international', make sure your tongue is curled up and lips are relaxed and slightly apart.
How is your rhythm? Don't say each syllable separately. Try to match the announcer's speed.
Remember: Your aim is not to sound like an announcer when you speak, but rather to train your ear to the different sounds in English.