Bound states in the continuum (BICs) have emerged as a powerful platform for enhancing wave-matter interactions, owing to their ultrahigh quality ($Q$) factors arising from extreme energy localization. While symmetry breaking in BIC-based metasurfaces can yield strong chiral responses, most existing studies have focused on single BIC systems, leaving their coupling and interactions largely unexplored. In this work, we propose a coupling-induced chiral quasi-BIC (QBIC) in an acoustic system. By introducing a coupling channel between a pair of BICs, perfect vortex patterns are observed in the far-field radiation at both ends, where the chiral responses are independently tunable for each port and maintain robustness against parameter perturbations. In a scattering network, the designed chiral QBIC exhibits maximum chirality-selective transmission for acoustic vortices, which is validated by an experimental prototype. Additionally, an exceptional line emerges in the parameter space of the scattering matrix as a non-Hermitian feature, revealing the origin of robust chirality and enabling tunability of the $Q$ factor. Our work provides an efficient way for chirality manipulation using BICs and may enrich the understanding of wave physics.

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• Acoustic metamaterials
• Bound states in the continuum
• Chirality
• Non-Hermitian systems