You may be a conscientious pronunciation student and do your drills before each lesson and you have finally mastered your voiced and unvoiced th's. However, the moment you sit down to lunch with your colleagues or have a drink with them at the pub and they revert back to Aussie talk or telling jokes you always feel that you are 5 minutes behind the conversation.
This is partly due to the very fast connected speech and partly due to the idiomatic speech used in conversation and also partly due to the shared cultural understanding when laughing and responding to humour. It will take a longer time to fully understand humour but you can work on it.
Pronunciation Matters courses are customised to your needs and if you need to be able to 'hold your own' at the pub after work we can work on this.
Today one of my clients said that at a meeting with a group of journalists he understood about a third of the jokes (as opposed to understanding none of them!) This was definitely a sign of progress.
How can you improve in this area? There are a number of great texts on listening to Australian conversation. Contact PM and I can direct you to those books. Listening to talk back radio such as Thank God it Friday on 702BL ( A Sydney ABC radio station)will also help.