Table 4.

Results of simple correlation analyses between vocabulary size at 25 months and different independent variables.

	Independent variables	r-value	p-value
Acoustic quality	Speaking rate	r(24) = 0.21	p = 0.29
of mothers’	Vowel space	r(15) = −0.09	p = 0.73
speech	F0	r(24) = −0.12	p = 0.56
	F0 range	r(24) = −0.10	p = 0.62
Quantity of	Number of tokens	r(24) = 0.13	p = 0.54
mothers’	Number of types	r(24) = 0.19	p = 0.35
speech	Token/type ratio	r(24) = 0.02	p = 0.92
	MLU	r(24) = 0.07	p = 0.75
Infants’ ability	Proportion looking to target	r(25) = 0.44	p < 0.05
to recognize words	Latency to target	r(25) = −0.05	p = 0.82