Table 3. Estimation accuracies of several estimators on human speech data in terms of RMS error, along with the parameters that define the estimator.

For estimators with no parameter β ₀, the coefficients β ₁…β ₄ correspond to those in Eq (4). For estimators with all five parameters listed, those parameters correspond to those in Eq (20). Note that the coefficient values for the maximum likelihood estimator, the proposed estimator, the maximum a posteriori estimator and the extended proposed estimator are mean values across all resamplings. Standard deviations of the coefficients β _1…4 for all estimators across all resamplings was < 0.015, and standard deviations of the coefficients β ₀ was < 10.

Estimator	β 0	β 1	β 2	β 3	β 4	RMSE (cm)
Freq. Dispersion		−0.167	0.000	0.000	1.167	4.125
F 4 only		0.000	0.000	0.000	1.000	2.621
Mean(F 3, F 4)		0.000	0.000	0.500	0.500	2.067
Max. Likelihood		0.041	0.149	0.441	0.369	1.556
Proposed		0.022	0.136	0.254	0.637	1.277
Max. a Post.	253	0.021	0.078	0.228	0.193	0.946
Proposed—Ext.	229	0.030	0.082	0.124	0.354	0.839