The study analysed spectral and tongue shape dynamics of voiceless alveolar and postalveolar fricatives produced by ten children learning Scottish English. Synchronised ultrasound tongue imaging data and acoustic data were used to characterise children's productions of the phonemic contrast. Six children had consistently accurate productions of…

Error patterns in children's phonological development are often described as simplifying processes that can interact with one another with different consequences. Some interactions limit the applicability of an error pattern, and others extend it to more words. Theories predict that error patterns interact to their full potential. While specific…