The neural mechanisms used by the human brain to identify phonemes remain unclear. We recorded the EEG signals evoked by repeated presentation of 12 American English phonemes. A support vector machine model correctly recognized a high percentage of the EEG brain wave recordings represented by their phases, which were expressed in discrete Fourier transform coefficients. We show that phases of the oscillations restricted to the frequency range of 2-9 Hz can be used to successfully recognize brain processing of these phonemes. The recognition rates can be further improved using the scalp tangential electric field and the surface Laplacian around the auditory cortical area, which were derived from the original potential signal. The best rate for the eight initial consonants was 66.7%. Moreover, we found a distinctive phase pattern in the brain for each of these consonants. We then used these phase patterns to recognize the consonants, with a correct rate of 48.7%. In addition, in the analysis of the confusion matrices, we found significant similarity-differences were invariant between brain and perceptual representations of phonemes. These latter results supported the importance of phonological distinctive features in the neural representation of phonemes. phase synchronization | EEG classification H ow the human brain processes phonemes has been a subject of interest for linguists and neuroscientists for a long time. From the beginning of the 20th century, behavioral experiments were carried out to explore the perceptual discrimination of phonemes under various conditions (1-5). Since 1978, Mismatch Negativity in EEG (6) has been used extensively to measure the neural discrimination of phonemes (7). These results suggest the existence of a language-specific phoneme representation (8). More recent findings (9-11) using magnetoencephalograph recordings support the brain's encoding of phonological features before the lexical information is retrieved. Invasive recordings of animal neural responses to human speech also exhibited temporal and spatial characteristics, reflecting the distinctive features of phonemes (12,13). Related research has shown that animal recordings from the auditory cortex match animals' behavioral discrimination of phonemes (14) as well as the pattern of human psychological confusions (15). Functional MRI (fMRI) provides a noninvasive method to locate cortical activities of phoneme perception in healthy human brains (16). Success in recognizing fMRI evoked by isolated vowels has also been reported (17), but this work is difficult to extend because of the limited temporal resolution of fMRI.In most EEG studies of phoneme perception, the interest has been in the temporal information rather than its spectral structure. However, it has been shown that EEG rhythms may be related to a specific cognitive state of the brain (18,19). In the present study, we show that we can recognize, with some success, brain representations of specific phonemes using only the phase properties of brain waves in a narrow...