The ideophone split is an internal hypothesis, unattested: *pa(a) as the thud of a heavy object dropping + -se 'emit the sound' (the ese / hose / wose pattern). The dictionaries give no compositional etymology; Vovin 1993 reconstructs *paasE (HLL) without internal analysis. Hokkaido dialects have short páse, all Sakhalin points paase with a long vowel (服部1964) — so the split requires a long ideophone *paa: plausible for an imitative thud and consistent with the pá- accent (an old heavy syllable), though the attested CV-se verbs (ese, hose, wose) all have short roots. The Sakhalin length neither supports nor contradicts the hypothesis.