Ranking Acoustic Cues for English Focus Prosody with Random Forests
Yong-cheol Lee · Studies in Linguistics · 2024
This study measured prosodic parameters related to English focus prosody, and ranked the cues that play a significant role in featuring English focus prosody using a random forest model. To achieve this research objective, we directly compared two focus conditions: broad focus and discourse-new focus. The broad focus condition was isolated, while the discourse-new focus condition was induced using a Q&A format. The findings revealed that both focus and post-focus regions exhibited distinct prosodic cues. In the focus regions, the primary distinguishing factor between the two focus conditions was duration, followed by intensity, pitch range, maximum pitch, mean pitch, and so on. Conversely, in the post-focus regions, mean absolute slope emerged as the foremost determinant in distinguishing between the two focus conditions. The remaining parameters were subsequently ranked in the following order: intensity, mean pitch, maximum pitch, duration, pitch range, minimum pitch, and so forth. In essence, different sets of acoustic cues demonstrated varying levels of influence on the focus and post-focus regions, each characterized by unique acoustic parameters, which ultimately defined the distinctive prosodic features of each region.