Table 3 Summary of the mixed effects linear regression model

	Estimate	Std. Error	df	t	Pr(>|t|)
(Intercept)	2.553	0.395	5.3	6.4	0.005
voice-voice	-1.050	0.523	4.1	-2.0	0.11
speedfast	-0.238	0.070	1492	-3.4	<0.001
speedslow	0.355	0.070	1492	5.05	<0.001
voice-voice: speedfast	0.195	0.099	1492	1.97	0.048
voice-voice: speedslow	-0.627	0.099	1492	-6.3	<0.001