# Within and Across-Language Comparison of Vocal Emotions in Mandarin and English
## 4 Discussion and Conclusions
### Multidimensionality of the Acoustic Realization of Vocal Emotions  
It is worth noting that in the within-language analysis, no direct comparison of each value between Mandarin and English was made, although the same experiment paradigm was used for both languages. Therefore, we further used normalized data to compare the different patterns of vocal emotions across languages. Each value of anger, fear, happiness and sadness was normalized against that of neutral emotion in each language, so that the derived data represented the proportion of changes for each emotion with neutral emotion as a reference. Based on the acoustic analysis on the normalized pitch-related cues, we observed that Mandarin and English showed different mechanisms when utilizing pitch to express vocal emotions. There were significant interactions between emotion and language on mean absolute slope, rise, fall, rise slope and fall slope. The pitch variations, with neutral as the baseline, were significantly greater in English compared to those in Mandarin. We posit that this difference is due to the restriction of pitch variation through the existence of lexical tones in Mandarin, since pitch is primarily used to maintain the tonal shapes in Mandarin in order to fulfil the distinction of meaning and, afterward, to realize paralinguistic functions. Although the present study is not the first to propose this idea [24; 25; 27], our study expands upon previous work in this area and provides additional objective measures. For example, this study included more sophisticated pitch measures which were able to better reflect the variation of pitch over time. Additionally, instead of comparing absolute values between Mandarin and English, we used derived values to reflect the magnitude of change certain cues showed in emotional speech given neutral as the baseline. That is to say, we measured the relative contribution of certain cues when differentiating among emotions. Distinct from the established literature that looked only at how paralinguistic use of pitch was influenced by the lexical tone system, we explored how other cues, such as duration, spectral and EGG cues, functioned when the restriction existed. Results showed that the differences between neutral and other emotions on speech rate, CPP, CQ and SQ were significantly greater in Mandarin than in English, which was opposite of the pitch-related cues results. A possible explanation for this might be that these cues were enhanced in Mandarin vocal emotions in order to supplement the suppressed pitch variation. Therefore, we believe our study provides new evidence regarding the pitch restriction hypothesis from a fresh perspective. Despite these promising results, several limitations remain in the way the study was conducted. First, given the limited number of tonal and non-tonal languages examined by the present study, one may argue that the differences between Mandarin and English vocal emotions may be due to different culture backgrounds of the speakers. Therefore, the conclusions need to be further tested by analysing a greater and more diverse pool of languages. The second limitation lies in the small sample number of speakers for each language. Thus, more speakers need to be recruited in future research to increase the generalizability of the study. In conclusion, this comprehensive study was conducted within and across-language between Mandarin vocal emotions and English vocal emotions with a set of prosodic cues, phonation-related spectral cues and EGG cues. Results revealed that within each language, different vocal emotions showed significantly different acoustic patterns. However, the pitch variation was suppressed in Mandarin vocal emotions due to the influence of lexical tone system when compared with those in English. Evidence from other cues supported the idea that when a certain dimension (for example, pitch) is restricted within a language, other dimensions may be strengthened in compensation. Thus, we posit that the acoustic realization of vocal emotions is multidimensional.