One Asian language that comes to mind is Thai. Having visited Thailand and spoken to friends about their language, it really displays how sounds and pitch are very important when trying to understand a Thai person or even more having them try understanding a Western person trying to speak the Thai language.

Almost all words in Thai have five different tones. The five tones are the following;
High Tone: This would be a normal voice just at a higher level.
Rising Tone: In English you might describe this as being surprised.
Mid Tone: This would be a normal speaking voice with no change in inflection.
Low Tone: Lower than your normal voice with no change in inflection.
Falling Tone: Hard accented tone with a strong falling inflection.

As in any language you will find some exceptions however I have never been able to get a good explanation for this one. The word is "seua" which has three meanings so only three tones The three meanings are tiger, mat and shirt.

I give this example to share a funny story from a friend who used to live in Thailand. He was trying very hard to speak Thai. It is very big challenge for any Western speaking person to speak Thai or many Asian languages. He went into a department store and asked the person if he could try on a shirt. The person looked at him strange. His Thai friend started to laugh. He had actually asked the person if he could try on a tiger.

How do you learn these types of languages? Like anything it takes practice. You must listen as much as you can to native speakers. You might watch movies or TV programs in those languages but most importantly you must concentrate on listening. You also can find audio clips of those words online and play them over and over. You can also record yourself speaking these words. Take a word with five different tones and record each one until you can say that they are close to the native sound. Maybe ask a native speaking person to listen and see if they understand what you recorded.

A great way to learn a language online is at http://www.exchangealanguage.com. Here you can find a native Thai person to help you make sure you try on that shirt and not the tiger. We have people from all around the world so no matter what language you are learning; you can find a language partner at http://www.exchangealanguage.com