Hi Julia,
Listening is one of the most difficult skills for ESL ss to aquire as it is something they are unable to learn. They can only improve it through practice.
I don ´t know what age or level your ss are, but this is what I do:
If they are younger , you can do this in class and if they are adults they can do it at home.
-First you explain to them that the object of the exercise is ´listening to listen ´ and not understanding what they hear.
-they will need a small log book to keep track of their progress
-start your ss as a warmer in class or have the adults do it at home using English television and in class, a tape script and you time it, starting with two minutes for the week and building it up gradually, eg: next week three mins, next week 4 mins, to a maximum of ten minutes , as it ´s not possible for ss to concentrate longer that 10 minutes at a time. During this two minute period they are to write down the words they hear, and then to count them everyday and log them up.
They ´ll [and you ´ll]be amazed at their own improvement over time.
You can also do running dictations, where the students have to change places with each piece of text that is read. The first is the scribe, second and third the runners, when nr.1 has finished writing the first piece they then change over.The first runner must now do the writing and the listening, while the other two run to get the info stuck on the wall.They have to remember the info and they should also spell it correctly , which means there is alot of running and authentic listening. To make it even more difficult , you could have some music playing the background too.
You could also give a small group a text , numbered and cut up, like a jigsaw, and each ss must dictate their piece to the group and they must write it down. Again you could put on some music and play with the volume, making it louder and softter to really make them listen.
Good luck
Rgds
Andrea ;o)