This study investigated the tendency of the human brain to respond to a standardized corpus of speech by measuring changes in speech-related EEG signals. Sixteen subjects listened to 120 standardized speech items for 8 seconds each, with 1-2 second intervals between the items and played randomly. The EEG signals were extracted during the listening process, the EEG signals in the frequency band of 1-40 Hz were preprocessed and analyzed, then compared them with speech signals. The results show that subjects have the same trend of EEG response when they hear the same standard speech. In addition, this paper also measured the phase difference between the EEG and speech signals by the phase-locked value method, which proved the functional connectivity between the EEG signals and speech quality. Furthermore, the EEG signals could distinguish the speech quality with a correct rate of 99.62%.