Process Density Index (PDI) scores in typically developing children between 3;0 to 7;0 years of age: Evidence from Dravidian Tulu

Various speech metrics have been developed to assess and monitor phonological development in young children. Process Density Index (PDI) is one such measure employed to determine the severity of phonological errors and speech intelligibility. The present study explored the utility of PDI as a measure of phonological development in 756 Tulu-speaking children between 3;0–7;0 years, across age and gender groups. Results revealed that the youngest group of children exhibited a higher number of phonological processes and a higher PDI score as compared to the oldest group. Children with higher PDI scores exhibited poorer speech intelligibility than those with lower PDI Scores. Further, a statistically significant gender difference with boys exhibiting higher PDI scores than girls with no interaction between age and gender was noted. The study finding provides an insight into the phonological aspects specific to Tulu language and suggests the utility of PDI as a potential clinical measure while assessing phonological issues.