Binds to but does not cross-link actin. Required for the formation and maintenance of inner ear hair cell stereocilia and staircase formation. Essential for normal hearing. Interacts with MYO3A (via C-terminus). Interacts with MYO3B (via C-terminus). Expressed in inner ear hair cells (PubMed:25582750). Expressed in utricle hair bundles (at protein level). Expressed in choclea (at protein level) (PubMed:26926603).