This article reports on a January-March 2025 instrumental-phonetic field mission in the Ubangi River Basin (Central African Republic), a severely under-documented sector of the MacroSudan Belt in which implosives, labial-velars, and other rare speech features are widespread across Bantu, Ubangi, and Central Sudanic languages. Following preliminary screening interviews with 125 speakers, acoustic, electroglottographic, and pneumotachographic (oral airflow and intraoral pressure) recordings were collected from 31 varieties (three to seven speakers each) using controlled non-word stimuli in fixed vocalic contexts, alongside a smaller set of real-word items. Preliminary case studies from Central Sudanic Bagiro illustrate the value of such instrumental-phonetic fieldwork: contrasts that appear weak or ambiguous in spectrograms alone (e.g. plosive vs. implosive bilabials, voicing oppositions in labial-velars, etc.) become transparent once laryngeal activity and pressure/flow dynamics are examined, in this case uncovering patterns consistent with glottalised articulations. Beyond documenting phonetic rara in a key contact zone, this article argues that high-resolution field phonetics is essential for refining phonetic and phonological typologies, providing an empirical basis for contact and historical reconstructions in the Congo and Ubangi areas specifically and the Macro-Sudan Belt more broadly.
Lorenzo Maselli (2025) studied this question.