How can express a sentence containing relative pronoun in Chinese?
Actually,

我不用再去参考[那些][中文]母语人士的发音了

would also make sense, since "refer to pronunciation" implies that you would "listen to those native speakers".  

If you want to save all words in your sentence, you may translate the attributive clause like this:

我不必再听那些可用来参考的母语人士的发音了。