In a distortion error, the speaker’s production of a target phoneme is altered in terms of acoustics or articulation, yet still resembles the intended sound. The distorted sound is not recognized as another valid phoneme of the language, but rather a deviant version of the correct phoneme (for example, a nasalized or lateralized articulation of /s/ that results in a lisp). Distortions often arise from motor or placement difficulties; they are commonly seen in residual speech sound errors such as persistent /r/ or /s/ misarticulations in older children and adults. Because the target sound is approximated but not correct, distortions can reduce speech intelligibility and are addressed in therapy by teaching the proper articulatory configuration.
Katarina L. Haley, Michael Smith, and Julie L. Wambaugh. “Sound Distortion Errors in Aphasia With Apraxia of Speech.” American Journal of Speech-Language Pathology 28, no. 1 (2019).
Peter Flipsen Jr. and Frances Pollock. “Children With Residual Speech Sound Errors: One Size Does Not Fit All.” Perspectives of the ASHA Special Interest Groups 1, no. 1 (2016).
