Table 1A.

Left and right canal plane unit normal vector coefficients (mean ± SD)

	XREID	YREID	ZREID	LA	LH	LP	RA	RH	RP	ZREID-R
XREID	1	0	1	−0.58954	−0.31645	−0.69611	−0.58905	−0.32891	−0.69248	0.00302
				± 0.06787	± 0.12805	± 0.06961	± 0.07930	± 0.11925	± 0.06477	± 0.00996
YREID	0	1	0	0.78750	−0.04108	−0.66820	−0.78928	0.03566	0.66561	0.00256
				± 0.04598	± 0.09289	± 0.06523	± 0.06425	± 0.10795	± 0.06852	± 0.00473
ZREID	0	0	1	−0.17971	0.94772	−0.26257	−0.17334	0.94369	−0.27826	0.99999
				± 0.09830	± 0.04707	± 0.10917	± 0.11482	± 0.04393	± 0.11218	± 0.00007

Each column lists the mean X_REID, Y_REID, Z_REID coefficients of unit length vectors perpendicular to each semicircular canal (mean ± SD, renormalized after averaging over N = 22 subjects so that the mean coefficients define a vector with unit length to within <10⁻⁵). As illustrated in Figure 4, the X_REID, Y_REID, and Z_REID coordinate system axes are the naso-occipital, left–right, and superior–inferior axes (+X_REID anterior, +Y_REID leftward, and +Z_REID superior) perpendicular to X_REID, Y_REID, and Z_REID, respectively, which are the coronal, midsagittal, and horizontal Reid's planes as defined in the text. Z_REID-R is ideally identical to Z_REID, but was measured using a CT image plane passing through the right external auditory canal (EAC) center point, rather than the left EAC as used for Z_REID.

L = left, R = right; A, H, P = anterior, horizontal, and posterior semicircular canals, respectively. Of the two antiparallel vectors normal to each plane, the vector pointing posterior of the Y_REID plane is listed (corresponding to those displayed in Figure 4B), so that right-hand rule (RHR) head rotations about LA, LH, and LP normal vectors would excite the LA, LH, and LP canals, respectively, while RHR rotations about the RA, RH, and RP normal vectors would inhibit the RA, RH, and RP canals.