Table 2.

Results of simple correlation analyses between vocabulary size at 19 months and different independent variables.

	Independent variables	r-value	p-value
Acoustic quality	Speaking rate	r(39) = 0.09	p = 0.57
of mothers’	Vowel space	r(26) = −0.02	p = 0.91
speech	F0	r(39) = −0.17	p = 0.30
	F0 range	r(39) = −0.11	p = 0.48
Quantity of	Number of tokens	r(38) = 0.31	p < 0.05
mothers’	Number of types	r(39) = 0.40	p < 0.01
speech	Token/type ratio	r(38) = 0.06	p = 0.72
	MLU	r(39) = 0.19	p = 0.22
Infants’ ability	Proportion looking to target	r(40) = 0.45	p < 0.01
to recognize words	Latency to target	r(40) = −0.35	p < 0.05