An Outline of Ìgás̩i Tone System

Abstract

Igasi and other related speech forms of North-west Akoko are critically endangered and studies of their phonologies are rare. This article reports that Ìgás̩í operates a terraced-level system with threetones, L, M, and H. The three tones of Igasi downdrift after L, but consonant voicing interacts with downdrift such that it is only attested when the intervening consonant is voiced; downdrift is not attested when there is a voiceless consonant between the L and the following tone. The language also has two phonetic contour tones, H͡ L falling, which is an allotone of L after H; and L͡ H rising, which is an allotone of H after L. While the falling contour tone is formed without inhibition, the rising contour is only formed when the L and H are directly adjacent to each other or when a voiced pre-vocalic consonant separates them. Consonant voicing interacts with L͡ H rising contour such that the rising is blocked when a pre-vocalic voiceless consonant intervenes between the L and H. Findings are supported with acoustic proofs.