Mediates electroneutral potassium-chloride cotransport when activated by cell swelling (PubMed:10913127). May mediate K(+) uptake into Deiters’ cells in the cochlea and contribute to K(+) recycling in the inner ear. Important for the survival of cochlear outer and inner hair cells and the maintenance of the organ of Corti. May be required for basolateral Cl(-) extrusion in the kidney and contribute to renal acidification (By similarity).