Table 2.

Statistical analysis of SNR and signal level on amplitudes, latencies, and area(50-550 ms) for Cz and GFP waveforms for the ONH and OHI groups (significance at alpha 0.05 in bold).

				Effect of SNR		Effect of Signal Level		SNR × Level Interaction
Group	Waveform	Metric	Peak	F-statistic (df)	P-value	F-statistic (df)	P-value	F-statistic (df)	P-value
OHI
	Cz	Latency	P1	51.9 (4, 54.9)	<0.001	1.4 (2, 34.0)	0.265	2.7 (5, 55.0)	0.032
			N1	69.4 (4, 70.1)	<0.001	4.7 (2, 46.3)	0.014	0.4 (5, 72.9)	0.861
			P2	20.0 (4, 38.7)	<0.001	1.2 (2, 16.9)	0.324	0.9 (5, 40.3)	0.467
			N2	5.2 (4, 38.7)	0.002	0.4 (2, 18.8)	0.695	0.5 (5, 35.3)	0.810
		Amplitude	P1	2.0 (4, 37.4)	0.119	1.3 (2, 127.1)	0.267	1.7 (5, 127.1)	0.143
			N1	12.8 (4, 29.5)	<0.001	1.4 (2, 117.0)	0.258	1.7 (5, 117.0)	0.132
			P2	6.3 (4, 38.0)	<0.001	1.5 (2, 99.1)	0.235	0.9 (5, 99.0)	0.466
			N2	1.3 (4, 54.1)	0.289	3.0 (2, 113.4)	0.055	0.5 (5, 113.7)	0.759
		Area		23.1 (4, 26.1)	<0.001	3.6 (2, 118.3)	0.031	1.0 (5, 118.3)	0.427
	GFP	Latency	N1	72.7 (4, 63.2)	<0.001	1.5 (2, 34.9)	0.237	0.5 (5, 64.4)	0.741
			P2	6.7 (4, 10.1)	0.007	0.8 (2, 4.4)	0.521	1.4 (5, 12.9)	0.285
		Amplitude	N1	11.7 (4, 26.3)	<0.001	3.1 (2, 106.3)	0.050	1.1 (5, 106.2)	0.386
			P2	9.4 (4, 45.6)	<0.001	0.7 (2, 64.3)	0.489	1.7 (5, 66.3)	0.138
		Area		18.5 (4, 27.6)	<0.001	5.7 (2, 122.6)	0.004	1.7 (5, 122.6)	0.147
ONH
	Cz	Latency	P1	25.6 (4, 60.4)	<.001	0.5 (3, 35.6)	0.680	0.8 (6, 68.3)	0.602
			N1	45.6 (4, 72.0)	<.001	0.4 (3, 43.7)	0.756	2.3 (6, 81.0)	0.045
			P2	22.8 (4, 68.2)	<.001	2.7 (3, 39.0)	0.058	3.1 (6, 66.0)	0.009
			N2	6.4 (4, 56.8)	<.001	0.5 (3, 35.3)	0.676	1.4 (6, 55.0)	0.228
		Amplitude	P1	5.2 (4, 48.8)	0.001	0.3 (3, 124.1)	0.845	0.9 (6, 123.9)	0.471
			N1	14.3 (4, 29.1)	<.001	0.6 (3, 139.2)	0.594	1.7 (6, 139.2)	0.122
			P2	21.9 (4, 38.5)	<.001	1.8 (3, 119.0)	0.151	0.9 (6, 116.3)	0.481
			N2	5.2 (4, 37.6)	0.002	0.6 (3, 111.7)	0.590	0.9 (6, 108.3)	0.467
		Area		17.8 (4, 25.7)	<.001	0.6 (3, 143.7)	0.641	1.7 (6, 143.7)	0.120
	GFP	Latency	N1	39.7 (4, 62.1)	<.001	0.4 (3, 36.4)	0.731	1.4 (6, 74.1)	0.217
			P2	17.8 (4, 46.0)	<.001	0.3 (3, 24.5)	0.830	0.2 (6, 47.3)	0.977
		Amplitude	N1	12.5 (4, 26.2)	<.001	1.3 (3, 128.5)	0.268	1.1 (6, 128.6)	0.368
			P2	15.0 (4, 29.2)	<.001	2.4 (3, 95.2)	0.070	1.0 (6, 95.1)	0.418
		Area		12.6 (4, 24.9)	<.001	0.2 (3, 144.4)	0.919	0.6 (6, 144.4)	0.766

SNR-signal-to-noise ratio, ONH-old normal hearing, OHI-old hearing impaired, df-degrees of freedom, ms-millisecond