My Yorùbá work asks whether generated speech preserves the distinctions that a fluent listener needs to understand an utterance. This is a natural language processing (NLP) problem grounded in the language itself: lexical tone, vowel distinctions and diacritics carry information that a fluent-sounding voice can still lose.
My contribution
I develop a workflow that brings together natural-speech references, structured listening judgments, acoustic measurements and reviewable annotations. I use the results to identify the next measurement or experiment, including cases where an intervention does not help.
Listening and acoustic evidence
I distinguish lexical tone from broader prosody, including rhythm and intonation. I also examine segmental pronunciation—the consonants and vowels—alongside transcript match, intelligibility, meaning recovery and naturalness. These questions stay separate so that a natural-sounding recording does not automatically receive credit for saying the intended words.
The acoustic workflow extracts fundamental frequency (F0, a measure related to pitch), voicing probability and RMS energy with pYIN, and compares pitch estimates with Praat/Parselmouth. Speaker-relative pitch representations help describe contours; missing values and disagreements between estimators remain visible. A pitch contour is evidence for inspection, not an automatic verdict on correct tone.
Language-aware preparation and independent review
The text pipeline preserves Yorùbá tone marks and underdots through Unicode normalization. Automatic alignment suggestions and human-verified timing remain separate. The independent boundary-annotation tool is designed for reviewers to mark syllable and tone-bearing-unit intervals, vowel or syllabic-nasal nuclei, and uncertainty without seeing one another’s annotations or prior scores. Its JSON exports preserve each reviewer’s evidence. Building the tool does not itself establish reviewer agreement or complete the annotation study.
What the pilot can establish
The listening results are small, single-rater, unblinded diagnostic findings. A matched prompt-guidance intervention produced no aggregate gain in tone correctness or naturalness. Whole-utterance pitch similarity is not lexical-tone accuracy, and these results do not establish provider rankings or population-level performance. Further model-adaptation training remains pending.