Table 2. Estimation accuracies of several estimators on simulated 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 < 0.005, and standard deviations of the coefficients β ₀ was < 5.

Estimator	β 0	β 1	β 2	β 3	β 4	RMSE (cm)
Freq. Dispersion		−0.167	0.000	0.000	1.167	1.692
F 4 only		0.000	0.000	0.000	1.000	1.206
Mean(F 3, F 4)		0.000	0.000	0.500	0.500	1.194
Max. Likelihood		0.083	0.122	0.192	0.604	0.683
Proposed		0.089	0.102	0.121	0.669	0.631
Max. a Post.	144	0.062	0.089	0.147	0.434	0.671
Proposed—Ext.	52	0.078	0.099	0.101	0.609	0.608