Table 3. Psychometric function analysis on visual enhancement data in Experiment 1.

Speaker-listener group	Fixed effects	Estimate	SE	t value	p
E-E	Intercept	0.26	0.03	8.16	<.001
	first-degree polynomial of SNR	−0.10	0.22	−0.45	.658
	second-degree polynomial of SNR	−0.97	0.22	−4.49	<.001
E-K	Intercept	0.11	0.02	4.37	<.001
	first-degree polynomial of SNR	0.19	0.21	0.90	.371
	second-degree polynomial of SNR	−0.50	0.21	−2.32	.023
K-E	Intercept	0.14	0.02	7.10	<.001
	first-degree polynomial of SNR	0.69	0.17	4.06	<.001
	second-degree polynomial of SNR	−0.13	0.17	−0.79	.430
K-K	Intercept	0.10	0.02	4.67	<.001
	first-degree polynomial of SNR	0.27	0.19	1.45	.151
	second-degree polynomial of SNR	−0.01	0.19	−0.04	.968