Figure 4.

Sound Transition Networks Showing Regular and Sporadic Changes

Transitions among consonants (circles) and among vowels (squares) are frequent and regular (many connections) but are rare between them, save for those mediated by the semivowel w. Transitions are more frequent among sounds with similar places of articulation: consonants are coded as bilabials-labiodentals (red), nasal (light green), uvular-velar-glottal (purple), postalveolar-palatals (blue), and dental-alveolars (green); vowels divide into high (gray) and higher-mid to low (white) subsets. Blue lines denote sporadic transitions, with thicker lines denoting faster underlying rates. Red lines denote regular changes; arrows indicate the direction of change.