Table 1.

Distribution of multisyllabic vocalization and chewing samples across age.

	Age (mos.)
	Age 1							Age 2
Behavior	8.2	9.1	9.3	10.2	12.0	13.2	14.3	16.3	17.1	19.2	21.3	Total
Babble
Vowel	9	28	15	7	0	7	1	3	2	2	2	76
Non-variegated	15	38	3	38	0	4	9	32	24	41	55	259
Variegated	1	3	1	2	0	1	3	22	17	24	16	90
Total	25	69	19	47	0	12	13	59	43	67	73	425
Nonspeech
Chewing	24	19	67	30	38	164	51	69	21	38	20	541