Subliminal priming refers to the effect of unconsciously processed prime on the cognitive processing of the related target. Subliminal priming studies have found that the semantic and emotional information of Chinese characters or words can be accessed without consciousness. However, most prior studies focused on the unconscious processing of visual words but ignored the unconscious processing of auditory words. The present study aimed to investigate unconscious processing of auditory words from Mandarin Chinese. The auditory masked priming paradigm is one of the most widely used tools to investigate the unconscious processing of auditory words. In a typical auditory masked priming study, a prime word, which is masked by a stream of time compressed speech-like sounds with similar spectral characteristics, is presented prior to the target word. Auditory masked priming studies using words from Indo-European languages only found a significant subliminal auditory repetition priming effect. However, studies using words from Semito-Hamitic languages also found a significant morphological priming effect. These results suggest that the mechanisms of subliminal auditory priming are different across different language families. While the subliminal speech priming of Indo-European and Semito- Hamitic has been investigated extensively, the subliminal speech priming of Mandarin Chinese has rarely been explored. Therefore, the present study, which included three experiments, used two- character Chinese words as materials to explore the psychological mechanism of subliminal speech priming of Mandarin Chinese using auditory masked priming paradigm. Experiment 1 was conducted with a 3 (time compression of the prime: 40%, 50%, 60%) x 2 (relation: related vs. unrelated) x 6 (prime condition: repetition, morphological, phonological, and semantic priming of word; repetition and first-character priming of nonword) mixed design to examine the processing level of the unconscious processing of auditory words from Mandarin Chinese. Experiment 2 was conducted with a 2 (voice change: same vs. different) x 2 ( relation: related vs. unrelated) x 2 (stimulus type: word vs. nonword) withinsubject design to examine whether the subliminal speech priming effect of Mandarin Chinese is influenced by the acoustic similarity between the prime and target. Experiment 3 manipulated the ISI (interstimulus interval) between the prime and the target to examine the duration of the subliminal prime processing. The results of Experiment 1 showed that participants were unaware of the primes at the 40% compression rate, and the response times (RTs) to related trials were significantly shorter than the RTs to unrelated trials in the repetition priming conditions for real words when the compression rate was 40%. These results suggested that the unconscious processing of subliminal Chinese words could facilitate the processing of the same word. The results of Experiment 2 revealed that the interaction effect between the prime-target relation and prime and target voice congruence was not significant, which indicated that subliminal repetition priming effects were not affected by acoustic similarity between the prime and the target. The results of Experiment 3 revealed a significant interaction between prime-target relation and the ISI between prime and target. The subliminal repetition priming effect was significant when the ISI was 0 ms, 208 ms or 416 ms but not when the ISI was greater than 416 ms. In sum, the present study explored the unconscious processing of two-character Mandarin Chinese words using auditory masked priming paradigm and found that the lexical information of two- character Mandarin Chinese words could be accessed without consciousness.
