Table 7.

Summary of hierarchical linear model for quality with processing speed (PS) as a predictor.

Fixed effect	Coeff.	Std. error	T-ratio	d.f	P-value
STEP 1
For Intercept
Intercept	0.412	0.020	20.783	26	<0.001
PS	0.059	0.031	1.905	26	0.067
For Slope
Fidelity index	1.119	0.038	29.827	26	<0.001
PS	−0.047	0.068	−0.629	26	0.495
STEP 2
For Intercept
Intercept	0.428	0.040	10.786		<0.001
PS	0.057	0.031	1.872		0.072
PTA	−0.000	0.001	−0.432		0.669
For Slope
Fidelity index	1.009	0.113	8.927	25	<0.001
PS	−0.038	0.067	−0.565	25	0.575
PTA	0.003	0.002	1.103	25	0.281
STEP 3
For Intercept
Intercept	0.239	0.095	2.525	24	0.019
PS	0.055	0.030	1.863	24	0.074
PTA	−0.000	0.001	−0.373	24	0.712
Age	0.003	0.001	1.968	24	0.060
For Slope
Fidelity index	1.102	0.274	4.018	24	0.001
PS	−0.037	0.067	−0.544	24	0.591
PTA	0.003	0.002	1.079	24	0.292
Age	−0.001	0.003	−0.383	24	0.705

Amount of hearing loss (PTA) is average of thresholds at 1, 2, 3, and 4 kHz in the test ear.