Historically, “rhotacism” refers to a speech impediment involving misarticulation of rhotic sounds /r/ (and sometimes /ɚ/ or /ɝ/ in English). Children with rhotacism may use a substitution like [w] (“wed” for “red”) or an incorrect oral posture that yields a distorted /r/ sound. The /r/ phoneme is one of the latest-developing sounds and one of the most challenging to master, which is why rhotacism is relatively common and can persist without intervention. In modern clinical practice, speech-language pathologists often describe these errors more specifically (e.g., “derhoticized /r/” or “/w/ for /r/ substitution”) rather than using the term rhotacism, but the term is still used informally to denote R-sound difficulties.
Peter Flipsen Jr. Remediation of /r/ for Speech-Language Pathologists. Plural Publishing, (2022).
Shriberg, Lawrence D. “Differential Diagnosis of Developmental Apraxia of Speech in Reference to Dysarthria and Speech Delay.” In The MIT Press Series in Speech and Hearing Sciences: Developmental Apraxia of Speech, edited by Lawrence D. Shriberg and Donald A. Campbell, 115–22. San Diego: College-Hill Press, (1987).
