Table 1.

Summary measures of the contingent and non-contingent stimuli by speaker vocalisation type, with fundamental frequency (F0) in Hertz, the period of silence (seconds:ms) and standard deviation of silence before trial onset markers began.

Speaker vocalisation type	Count	Mean F0	Minimum F0	Maximum F0	Minimum to maximum period of silence before trial onset (seconds:ms)	SD silence before trial onset (ms)
Infant Contingent	89	312	238	392	00:17 – 01:49	400
Infant Non-contingent	61	286	201	385	02:01 – 04:88	700
Mother Contingent	96	285	168	416	00:20 – 01:48	340
Mother Non-contingent	75	247	205	386	02:04 – 04:98	740