The development of vowel length as a subphonemic cue

Abstract

Previous research has shown that English speakers use vowel length (VL) as a subphonemic cue to obstruent voicing. Many studies have demonstrated adults’ ability to make a voicing judgment based upon VL but studies with children have provided mixed results. In the present study, we sought to first determine whether adults would exhibit varying sensitivity to VL based upon whether it could serve as a strong subphonemic cue. Second, we sought to better understand children’s sensitivity to subphonemic VL from 4 to 6 years by removing top-down information and isolating the acoustic system. Adults (NN=73, MEAN AGE=5;5.6) treat subphonemic VL differently from adults in two ways. First, they fail to show sensitivity at the same level as adults. 5- and 6-year-olds require VL differences that are twice as large and 4-year-olds do not show sensitivity even at the larger lengths. Second, children do not reveal varying sensitivity based upon the vowel’s position as a potential subphonemic cue. This suggests that children have not fully developed their native phonology by the time they are 6-years-old.