Which Speech Sound Norms Are Used in U.S. Public Schools? A Retrospective Survey Analysis.

Normative data concerning speech sound acquisition are widely and heavily used in the United States to determine eligibility for services. Normative studies differ in the age and geographic location of participants, which can limit applicability across the United States. In 2016, we queried school-based speech-language pathologists (SLPs) in the United States using a web-based survey to determine which speech sound norms are used. Nine regions from the U.S. census were represented. The Iowa-Nebraska norms were most commonly reported. However, many SLPs were unable to name the source of the data that they used. More than 60% of the sample indicated that they referred to one source of normative data. Results of a logistic regression indicated that region of the United States predicted if SLPs used one or multiple sources. Specifically, SLPs in the West North Central region of the United States (which includes Iowa and Nebraska) were more likely to use only one source of data, the Iowa-Nebraska norms. We recommend that speech sound norms are less heavily relied upon for eligibility decisions, particularly due to the substantial variations in culture and dialect throughout the various regions of the United States.