The perception of vowels such as [a] or [i] is based on their spectral properties, i.e. resonance frequencies (formants), and on fundamental frequency (f0). Yet, it is unclear whether early neural indices of vowel processing are predominantly driven by f0 or by formant frequencies.

A candidate neural index of early acoustic processing is the N1, a negative evoked potential of the human electroencephalogram (EEG), peaking between 80 and 150 ms after stimulus onset. The N1 has been found to reflect pitch differences in simple tones, but also general vowel differences. However, the relative contributions of formant frequencies and f0 to N1 amplitudes and latencies are not entirely clear.

To this end, an EEG study on German vowels differing in both first (F1) and second (F2) formant as well as f0 (independently modified) was conducted. Results showed that f0 only influenced N1 latencies of vowels with low F1, while F1 influenced amplitudes and latencies for all vowels. The distance between F1 and F2 as well as F2 significantly correlated with N1 amplitudes, but not with N1 latencies. These results imply that early neural processing of vowels relies on higher spectral components (formants) rather than f0.

对元音（例如[a]或[i]）的感知是基于它们的频谱特性，即共振频率（共振峰）和基频（f0）。然而，不清楚元音处理的早期神经指标是否主要由f0或共振峰频率驱动。

早期声学处理的候选神经指标是N1，即人类脑电图（EEG）的负诱发电位，在刺激发作后80到150 ms之间达到峰值。已经发现N1可以反映简单音调中的音高差异，也可以反映一般的元音差异。但是，共振峰频率和从f0到N1的幅度和延迟的相对贡献尚不完全清楚。

为此，对德国元音进行了一次脑电图研究，该元音在第一（F1）和第二（F2）共振峰以及f0（独立修改）中均不同。结果表明，f0仅影响低F1元音的N1延迟，而F1影响所有元音的振幅和延迟。F1和F2以及F2之间的距离与N1振幅显着相关，但与N1延迟无关。这些结果表明，元音的早期神经处理依赖于较高的频谱分量（共振峰），而不是f0。