 has been shown to track not only the acoustic features in speech, for example the temporal envelope, but also the abstract hierarchical linguistic information embedded in speech. As reported by Dean at all in their 2016 study, the spring tracking activity has a potential to be developed as a neuro marker of speech understanding in noise because it offers concurrent but dissociated tracking response to different levels of linguistic units, for example the syllables, the phrases and the sentences. In our study, we've tested 19 participants and recorded EEG data from them to evaluate the sensitivity of this tracking response to changes in background noise by introducing multi-talker bubble noise to the speech material. Our results showed that the tracking response is indeed sensitive to changes in background noise. However, the pattern of changes differs at different linguistic units at the syllable level. It's more corresponding to the changes in the acoustic signal whereas at the phrase and the sentence level, the changes are more related to the changes to perceived speech intelligibility. For more details of the study, please listen to our full presentation. Thank you.