Table 4.

Results of Linear Mixed Effects model results on d' and reaction times for normally hearing adults listening to unprocessed and spectrally degraded speech. In the interest of clarity, only significant effects are shown.

		d'					Reaction Time
		β	SE	df	t	p	β	SE	df	t	p
Overall Performance	Age	−0.023	0.004	94	−6.55	<0.001	0.022	0.003	46	7.47	<0.001
	Male Talker (ref: Female Talker)	−0.378	0.144	296	−2.63	<0.01	-	-	-	-	-
	Degree of Spectral Degradation (ref: Full Spectrum)
	16 Channel	−1.68	0.188	296	−9.00	<0.001	-	-	-	-	-
	8 Channel	−2.51	0.184	296	−13.59	<0.001	-	-	-	-	-
	4 Channel	−2.76	0.186	296	−14.85	<0.001	-	-	-	-	-
	Age x 16 Channel (ref: Full Spectrum)	0.008	0.004	297	2.52	0.01	-	-	-	-	-
	Age x 8 channel (ref: Full Spectrum)	0.014	0.003	295	4.01	<0.001	-	-	-	-	-
	Age x 4 Channel (ref: Full Spectrum)	0.015	0.004	296	4.22	<0.001	-	-	-	-	-
	Male Talker x 16 Channel (ref: Female Talker, Full Spectrum)	−0.567	0.115	295	−4.92	<0.001	0.22	0.073	161	3.06	<0.01
	Male Talker x 8 Channel (ref: Female Talker, Full Spectrum)	−0.329	0.114	295	−2.89	<0.01	-	-	-	-	-