In order to be heard over the low-frequency energy of a loud orchestra, opera singers adjust their vocal tracts to increase high-frequency energy around 3,000 Hz (known as a “singer9s formant”). In rap music, rhymes often coincide with the beat and thus may be masked by loud, low-frequency percussion events. How do emcees (i.e., rappers) avoid masking of on-beat rhymes? If emcees exploit formant structure, this may be reflected in the distribution of on- and off-beat vowels. To test this prediction, we used a sample of words from the MCFlow rap lyric corpus (Condit-Schultz, 2016). Frequency of occurrence of on- and off-beat words was compared. Each word contained one of eight vowel nuclei; population estimates of each vowel9s first and second formant (F1 and F2) frequencies were obtained from an existing source. A bias was observed: vowels with higher F2, which are less likely to be masked by percussion, were favored for on-beat words. Words with lower F2 vowels, which may be masked, were more likely to deviate from the beat. Bias was most evident among rhyming words but persisted for nonrhyming words. These findings imply that emcees use formant structure to implicitly or explicitly target the intelligibility of salient lyric events.

中文翻译：

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元音共振峰结构预测嘻哈歌词中的公制位置

为了听到响亮乐团的低频能量，歌剧演唱者调节其声道以增加3,000 Hz附近的高频能量（称为“ singer9s共振峰”）。在说唱音乐中，节奏通常与节拍重合，因此可能被响亮的低频打击乐事件掩盖。主持人（即说唱歌手）如何避免掩盖节奏韵律？如果司仪使用共振峰结构，这可能会反映在节拍的元音和非节拍的元音中。为了测试这一预测，我们使用了MCFlow rap语料库中的单词样本（Condit-Schultz，2016）。比较了节拍音的出现频率。每个单词包含八个元音核之一；每个元音的第一和第二共振峰（F1和F2）频率的总体估计是从现有来源获得的。观察到偏差：具有较高F2的元音（不太可能被打击乐器掩盖）更适合作为节拍单词。具有较低F2元音的单词（可能会被掩盖）更可能偏离节拍。偏见在押韵词中最明显，但对于非押韵词仍然存在。这些发现暗示主持人使用共振峰结构隐式或显式地针对显着歌词事件的可理解性。