The most important element in the study of communication, particularly cross-cultural communication, is avoiding any form of pre-conceived notions of the culture that needs to be communicated with. Once we avoid pre-conceived notions and focus completely on the idiosyncrasies of the cultural group, we will be able to lesser the noise, lower the affective filter, and create better understanding.
The first step to reduce the noise is understanding the cultural field of the individual, reducing unneccesary use of words, gestures, and descriptors.
Secondly, you must watch your own non-verbal communication and ensure that you understand those of the client from a different culture.
Maintain a current log of information that pertains to the psychology and sociology of the culture. Do not have expectations. Ensure that the message is encoded and decoded correctly. Always paraphrase, and again, beware of pre-conceived notions.
Remember that noise is interference. It can be linguistic (misunderstanding of words), non-verbal (misunderstanding of gestures), but it could also be produced by bias and by threatening conditions in the environment. For example, if you are communicating with a client from Iran and you hear information that may make some people feel threatened, the entire environment is going to be affected and the noise will not allow for mutual understanding due to bias.
Therefore, going back to the beginning the elimination of bias is the first step to the process.
The only way to significantly reduce the level of "noise" in cross-cultural communication is through education. Business people who are going to deal with people from another culture must be educated to some degree in the cultural idiosyncrasies of that other culture. They must be taught how that second culture differs from their own.
This is the only way to really reduce noise because noise is a function of cultural difference. Noise exists when there is something going on in the process of communication that distracts from the actual substance of the communication. For example, if a business person goes to another country and is having a business meeting, he may be put off if the other person keeps touching him or if the other person stands too near to him. This may be normal in the other persons culture, but it is distracting and causes "noise."
The only way to reduce this problem is for the business person to be educated about what to expect so that the unfamiliar cultural behaviors will not distract him as much as they otherwise would.