Consonantal F perturbation in American English involves multiple mechanisms.

In this study, we revisit consonantal perturbation of F in English, taking into particular consideration the effect of alignment of F contours to segments and the F extraction method in the acoustic analysis. We recorded words differing in consonant voicing, manner of articulation, and position in syllable, spoken by native speakers of American English in both statements and questions. In the analysis, we compared methods of F alignment and found that the highest F consistency occurred when F contours were time-normalized to the entire syllable. Applying this method, along with using syllables with nasal consonants as the baseline and a fine-detailed F extraction procedure, we identified three distinct consonantal effects: a large but brief (10-40 ms) F raising at voice onset regardless of consonant voicing, a smaller but longer-lasting F raising effect by voiceless consonants throughout a large proportion of the following vowels, and a small lowering effect of around 6 Hz by voiced consonants, which was not found in previous studies. Additionally, a brief anticipatory effect was observed before a coda consonant. These effects are imposed on a continuously changing F curve that is either rising-falling or falling-rising, depending on whether the carrier sentence is a statement or a question.