Category boundaries

Categories are determined when the corresponding analysis is performed, e.g., when a display is drawn or data are saved. Automatically determined values are displayed in Arabic numbers (1, 2, 3, 4). Categories set by hand are displayed by Roman numerals (I, II, III, IV). Category boundaries are taken from (Van As, 2001, Table 5.4 p88) and here indicated by Roman numerals for clarity.

•  Voiced Fraction:
•   I < 90.2% < II < 77.45% < III < 50% < IV (VF < 50% is IV also for F₀ sd and Jitter)
•  F₀ standard deviation:
•   I < 3.360 < II < 7.495 < III; IV if Voiced Fraction < 50%
•  Jitter:
•   I < 5.3% < II < 8.05% < III; IV if Voiced Fraction < 50%
•  Mean Harmonicity:
•   I > 7.195 > II > 4.050 > III > 1.925 > IV (dB)
•  GNE:
•   I > 0.820 > II > 0.795 > III > .745 > IV
•  BED:
•   I > 23.85 > II > 19.95 > III > 13.50 > IV (dB)

The final automatic AST category is defined as the median of the individual measures.

Links to this page

• Acoustic Signal Typing
• Determine pathological type
• Example evaluating AST
• Perceptual rating of a vowel