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Vegetal wools, composed of vegetal fibers and bicomponent polymer fibers, offer highly relevant multifunctional properties for green buildings but exhibit limited low-frequency acoustic absorption when used in thin panels. To optimize their performance, it is possible to rely on self-consistent homogenization methods. However, these methods require key data such as porosity and the effective radius of the fibres. However, vegetal wools present particular challenges due to the non-cylindrical shape of their fibres and the high polydispersity of their fiber diameters, making it necessary to analyze the distribution of their fiber diameters.This study establishes a measurement protocol using scanning electron microscopy (SEM) to observe the cross-sections of several vegetal wools, approximating fiber profiles as ellipses to establish radius probability distributions. Four averaging methods are evaluated to determine the most appropriate effective radius for modeling.Three self-consistent models, Tarnow-Brinkman, Umnova-Johnson-Champoux-Allard-Lafarge, and Piégay, are used to simulate visco-inertial and thermal effects. A direct approach (single effective radius) and a composite approach (two effective radii distinguishing fiber types) are compared for sound absorption calculations. The simulation methods are then evaluated against acoustic measurements to identify the most accurate analytical estimates.This analysis concludes that, to calculate static airflow resistivity, it is preferable to use Tarnow's model in a direct or composite approach, taking as the effective radius an arithmetic or quadratic average. For sound absorption, the best approaches are those of Umnova-Johnson-Champoux-Allard-Lafarge in a direct or composite approach, and Piégay's in a composite approach with an arithmetic average radius.