Horizontal semicircular canal responds to
The three canals lie at right angles to each other but the one which lies at right angles to the axis of rotation is stimulated the most.Thus horizontal canal will respond maximum to the rotation on the veical axis. (Ref: Diseases of EAR, NOSE and THROAT by PL Dhingra; 6th edition; page no.17)
Horizontal acceleration
Rotational acceleration
Gravity
Antero-posterior acceleration
Ear