Experiment 3: Vowel quality at F1 peak vs. midpoint

• Vowel is better characterized at F1 peak than at midpoint
• LAFF labelers seem to place Vowel landmarks at midpoint

• F1 has proper peak, not at endpoints
• F1 clear and measurable, without nasalization, glottalization or aspiration
• Landmark location in LAFF database is important

• Use only proper vowels (not schwas and syllabic sonorants)
• Use only vowels with proper peaks (not at endpoints)
• Do not use shibboleth utterances (sa1 and sa2)
• Result is 37008 tokens (27062 train, 9946 test)

• Formant values taken at F1 amp peak and at midpoint
• K Nearest Neighbors (KNN) classification
• Euclidean distance metric (first three formants)
• K = sqrt(N)

• Not much performance difference between F1 peak and midpoint
• McNemar test shows significant difference
• Ambiguous, but location does not appear critical