Aminoglycoside (AG) enters into hair cells (IHCs and OHCs) through mechanotransducer (MET) (1), transient receptor potential (TRP) (2), adenosine triphosphate (ATP) receptor (3) channels, and endocytosis (4). Lower number depicts stronger evidence (1 > 2 > 3 > 4). Each star indicates the location of the channels or endocytosis in hair cells (pink, IHC stereocilia; yellow, OHC stereocilia; brown, IHC cell body; blue, OHC cell body).