Pairwise Variability Index (PVI)

English is a stress-timed language, meaning unstressed syllables are aggressively compressed (reduced to schwa) to maintain rhythm. Syllable-timed language speakers often fail to reduce unstressed syllables.

Clinical Notes

Relying on auditory feedback alone for this metric is proven to be ineffective in adult language learners. Biometric feedback is required to remap established motor patterns.