Table 2. Effects of context and ontogenetic phase on sound features.

Results refer to parametric two-way ANOVAs in the case of sound duration, number of pulses and pulse period following data transformations and to the equivalent non-parametric test for peak frequency. Fifty sounds were considered per ontogenetic class and context (see Materials and Methods for details).

	Sound duration (ms)			Number of pulses			Pulse period (ms)			Peak frequency (Hz)
Factors	df	F	p-value	df	F	p-value	df	F	p-value	df	H	p-value
Context	1,194	61.08	<0.001	1,189	21.21	<0.001	1,189	155.51	<0.001	1	83.21	<0.001
Ontogenetic phase	1,194	9.62	0.002	1,189	18.16	<0.001	1,189	0.67	0.41	1	1.45	0.23
Interaction	1,194	0.02	0.88	1,189	0.19	0.67	1,189	3.35	0.07	1	3.50	0.06