Abstract: Precategorical acoustic storage (PAS) is described as a limited capacity buffer store in which acoustic traces are overwritten by successive auditory events. The goal of this study is to extend the function of PAS by investigating whether the recency effect and the suffix effect could also be found when Mandarin lexical tones and emotional tones are recalled in a serial order. Four experiments were conducted. In Experiments 1 and 2, participants were asked to recall lexical tones in a serial order. In these experiments, the recency effect and the suffix effect were found. In Experiments 3 and 4, emotional tones were required to be recalled in a serial order. Both effects were also found. The results of our current study suggest that lexical tones and emotional tones are represented independently in PAS, but their representation status is affected by the attributes of suffix. The results also implied that representations of Mandarin pitch patterns were not as stable as segmental fragments, revealing their special status in short-term memory processing.
A serial of lexical tones served as experimental stimuli in Experiments 1 and 2. In Experiment 1, 20 undergraduates were required to give immediate serial recall of the lexical tones presented auditorily via speech. In Experiment 2, a suffix was presented at the end of each serial of lexical tones. Another 20 undergraduates were asked to verbally report the serial as soon as the suffix disappeared. In that lexical tones have a close relationship with vowels, four types of suffixes were prepared at the end of each serial and were further compared with the results of Experiment 1. The results of the two experiments indicated that lexical tones, regardless of suffix type, showed a similar recency effect and suffix effect as vowels in serial recall performance. These findings imply a representation in PAS.
A serial of emotional tones served as experimental stimuli in Experiments 3 and 4, which aimed to discover whether emotional tones also show the recency effect and the suffix effect, thus represented in PAS as well. The suffix in Experiment 4 was either consistent or inconsistent with the final item’s emotional information. The results of Experiment 3 indicated that emotional tones reveal a recency effect in the serial recall task. The results of Experiment 4 were compared with those of Experiment 3, and it was found that emotional tones had the suffix effect only when the emotional information of the suffix was inconsistent with that of the final item. The relationship between the suffix and the final item may be a critical factor that causes the suffix effect.
Our results are consistent with the notion that PAS, as a sensory memory system, is a storage that can represent and process various aspects of speech information in a similar way. Further implications of our findings are also discussed in terms of specific attributes of lexical tones and emotional tones.

Key words: precategorical acoustic storage, suprasegmental information, lexical tones, emotional tone