Tonal languages use pitch variations to convey semantic meanings, in which different tones are applied on syllables to express lexical distinctions. Through sound weakening and tonal contour changes, a syllable in Standard Chinese Mandarin could be tone-neutralized into a weak unstressed neutral tone (T0). Around 5% of Chinese compounds present such a prosodic pattern by carrying a neutral tone on their second constituent. Linguistically, this particular morphological structure attested in Mandarin offers a relevant case study in psycholinguistics to address the question of the prosody-morphology relation in auditory compound recognition. Recent neurophysiological studies (Isel & Shen, 2020; Isel & Shen, submitted) suggest that native speakers of Mandarin use the neutral tone as an access code to trigger a retroactive computation on the semantic properties of the whole word, i.e. the compound. To extend the series of studies initiated by Isel and Shen with native speakers of Mandarin, the present project addresses the question of whether second language speakers of Mandarin use the neutral tone while perceiving Mandarin compounds. More specifically, we ask whether lexical frequency of the compound and proficiency in Mandarin (L2) may affect the processing of tonal information in bilinguals. Based on a brief description of dual-route models of morphological complex word recognition (Isel, Gunter, & Friederici, 2003; Isel, 2010; Isel & Shen, 2020), an overview of the interaction between prosodic information and morphological structure during processing of spoken compound will be reported. Furthermore, language-related neurophysiological markers associated with the auditory processing of polymorphemic word will be introduced. Finally, the experimental program of my PhD will be presented with particular emphasis on the relevance of these neurophysiological markers to investigate the underlying language processes involved in T0 Mandarin compound recognition.