Table 1.

Effect of modulation depth on parameters of the temporal modulation transfer function Decreasing modulation depth is associated with significantly decreased tMTF bandwidth, corner frequency, and cut-off frequency. Best modulation frequency is independent of modulation depth. Data are expressed in octaves and as mean values (95% confidence interval), relative to that at m= 1. P value indicates the outcome of ANOVA. For analysis of the effect of modulation depth on bandwidth, only those tMTFs classified as ‘band-pass’ were included.

		Modulation depth, m
	Unit type	0.5	0.25	0.13	0.06	P
Δ BMF						0.57
	PL	−0.16	0.0	−0.07	−0.27
		[−0.72, 0.40]	[−0.43, 0.43]	[−0.53, 0.39]	[−0.72, 0.17]
	CT	−0.09	−0.11	−0.25	−0.26
		[−0.25, 0.07]	[−0.32, 0.11]	[−0.57, 0.07]	[−0.68, 0.16]
	CS	0.08	0.09	0.14	0.07
		[0.0, 0.15]	[0.0, 0.18]	[−0.01, 0.27]	[−0.12, 0.27]
Δ Bandwidth						< 0.01
	PL	−0.79	−0.66	–	–
		[−1.4, −0.18]	[−1.3, −0.06]
	CT	−0.45	−0.72	−0.77	−0.82
		[−0.64, −0.27]	[−1.0, −0.44]	[−1.12, −0.43]	[−1.3, −0.35]
	CS	−0.41	−0.55	−0.83	–
		[−0.54, −0.28]	[−0.70, −0.40]	[−1.2, −0.41]
Δfcorner						< 0.01
	PL	−0.30	−0.44	−0.82	−
		[−0.54, −0.07]	[−0.58, −0.32]	[−1.2, −0.44]
	CT	−0.30	−0.59	−0.86	−0.77
		[−0.40, −0.20]	[−0.73, −0.44]	[−1.1, −0.64]	[−1.1, −0.49]
	CS	−0.17	−0.24	−0.42	−0.41
		[−0.23, −0.11]	[−0.32, −0.17]	[−0.60, −0.23]	[−0.86, 0.05]
Δfcut-off						< 0.01
	PL	−0.27	−1.0	−1.5	−2.5
		[−0.56, 0.03]	[−1.5, −0.45]	[−2.1, −0.97]	[−3.0, −1.9]
	CT	−0.40	−1.1	−1.8	−2.3
		[−0.52, −0.29]	[−1.3, −0.81]	[−2.1, −1.4]	[−2.7, −1.9]
	CS	−0.40	−0.88	−1.5	−2.1
		[−0.55, −0.24]	[−1.0, −0.72]	[−1.7, −1.2]	[−2.3, −1.9]