This paper addresses the acoustic realisations of the pretonic vowels /e, o/ that have been previously reported to undergo regressive vowel harmony in Brazilian Portuguese. It examines how the height of pretonic /e, o/ is affected by the phonological and phonetic height of the adjacent stressed vowel in three dialects: Northeastern (Bahia), Northern (Amazonas) and Southern (Rio Grande do Sul). A pseudoword reading task was performed with two speakers each of the three different dialects. The findings suggest that there is some kind of low harmony, in that /e, o/ are realized with markedly higher F1 before the stressed low vowels /ɛ, a, ɔ/ than before the stressed non-low vowels /i, e, o, u/. This effect was found for all dialects, but appears to be categorical (and thus phonological) for the Northern and Northeastern speakers, while gradient for the Southern speakers, where it is likely due to phonetic V-to-V coarticulation. More importantly, no effect of height harmony was found in any of the dialects: pretonic /e, o/ were not produced significantly higher before a stressed /i, u/. In addition, Northern and Southern speakers showed V-to-V coarticulation for the non-high pretonic vowels, illustrating with Northern speakers that a categorical harmony process can co-occur together with a gradient vowel assimilation in the same dialect.

中文翻译：

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巴西葡萄牙语前音调元音的梯度和分类同化

本文讨论了前声调元音 /e、o/ 的声学实现，之前曾报道过这些元音在巴西葡萄牙语中会发生回归元音和声。它检查了三个方言中相邻重读元音的语音和语音高度如何影响前调音 /e、o/ 的高度：东北（巴伊亚）、北方（亚马逊）和南方（南里奥格兰德）。使用三种不同方言中的每一种的两个说话者执行伪词阅读任务。研究结果表明存在某种低和声，因为 /e, o/ 在重读低元音 /ɛ, a, ɔ/ 之前的 F1 明显高于重读非低元音 /i, e, o，你/。在所有方言中都发现了这种效果，但对于北方和东北部的说话者来说似乎是分类的（因此是语音的），而南方说话者的梯度，可能是由于语音 V-to-V 发音。更重要的是，在任何方言中都没有发现高度和谐的影响：在重读 /i、u/ 之前，前调 /e、o/ 没有显着提高。此外，北方和南方的说话者对非高前调元音表现出 V 到 V 的共同发音，向北方说话者说明，在同一方言中，分类和声过程可以与梯度元音同化同时发生。