To untrained ears, the various forms of the Chinese language sound the same, despite its many dialectical differences. This is just one of the difficulties faced by many looking to understand or learn the language. It becomes even more complex given the differences between spoken and written Chinese, which contribute to it being one of the most difficult languages in the world to study.
In Hong Kong, for example, Cantonese is the main Chinese language spoken. It is written very much like Mandarin, which is regarded as standard Chinese. The characters used in Hong Kong are, however, traditional and not the simplified version. But when it is read, the pronunciation is Cantonese so that it can be understood in this territory. In Cantonese, Hong Kong would sound like heong gong. In its written form, it would sound like siang gang when read in standard Chinese, based on the characters used. So even if someone is unfamiliar with Cantonese, it is highly probable to associate “heong gong” with Hong Kong but not when they hear “siang gang.”
While pronunciation is one of the marked differences among dialects, there are also differences in grammar and vocabulary; Chinese characters are not phonograms (representing vocal sounds) but rather ideograms (representing an idea). As such, the written Chinese characters will not give you any information as to how they are pronounced, because each character in Chinese is pronounced based on the dialect used.
It should be noted that even if there are differences in spoken Chinese, the rule is to write the characters in standard Chinese or Mandarin Chinese, even if traditional or simplified characters are used.
In many regions in China where Mandarin is not used, people still have to learn how to write in Mandarin, which is different from the language or dialect they speak. It’s a burden for them, and it presents a real challenge to translators as well