Development and measurement of psychometric properties of the Persian test of speech consistency in children with typical development.

The current research pursues the study of developing the Persian test of speech consistency and investigating speech consistency in normally developing children in Iran. After developing the Persian test of speech consistency, the obtained speech samples of 317 participants (163 girls and 154 boys) were analyzed. This test of consistency includes 27 items. Experts' consensus over the characteristics of the Persian test of speech consistency was above 85%. Different age groups had statistically significant differences for the mean scores of the variable responses (p < .001), consistent correct (p < .001), and consistent incorrect responses (p = .007) in the Persian test of speech consistency. Also, there was a high value for the inter-rater reliability (ICC = .88, p < .001) as well as the moderate value for the test-retest reliability (ICC = .89, p < .001). The Persian test of speech consistency is regarded as a reliable and valid scale for measuring the speech consistency in Persian-speaking children. Future studies are proposed to investigate the speech consistency in Persian-speaking children with various kinds of speech sound disorders.