Table 1. Descriptive statistics (N = 20) and tests of equality of group means between individuals for each of the acoustic measures used in the DFA.

Acoustic measures	M	s.d.	Minimum	Maximum	Wilks' lambda	F19,256	P
Duration	38.51	12.23	20.57	70.14	0.712	5.438	<0.001
Mean F0	27.07	5.77	18.95	40.69	0.610	8.613	<0.001
Maximum F0	61.45	12.18	32.80	82.80	0.663	6.848	0.085
Minimum F0	9.80	0.76	8.76	11.54	0.900	1.500	<0.001
Jitter	5.75	0.50	4.94	6.54	0.794	3.499	<0.001
Ampvar	14.11	1.89	10.82	17.30	0.531	11.908	<0.001
F1	216.94	17.85	186.27	247.57	0.539	11.505	<0.001
F2	416.68	28.92	362.50	465.13	0.337	26.557	<0.001
F3	660.79	55.26	560.00	772.67	0.390	21.050	<0.001
F4	1155.96	134.51	922.10	1360.25	0.117	101.622	<0.001
F5	1618.40	105.97	1427.27	1812.13	0.209	51.123	<0.001
F6	2131.99	143.23	1845.87	2473.20	0.270	36.513	<0.001
ΔF	355.81	23.12	312.16	405.29	0.139	83.131	<0.001

See text for definition of variables.