Contributions of pitch and spectral information to cortical vowel categorization

•Spectral and periodicity properties of vowels are investigated using EEG.•The component of interest (N1) is sensitive to both properties in complex sounds.•We compared matched speech and non-speech based on f0 and F1 frequencies.•In a matched setup, N1 properties were influenced by f0 only to a small degree.•Early vowel processing is dominated by spectral information.