How do 'sound distortions' differ from 'substitutions' in AOS?

• A. Distortions involve inaccurate articulation of a target phoneme, whereas substitutions replace a phoneme with a different one.
• B. Distortions are only voicing errors
• C. Substitutions involve improved articulation
• D. Distortions occur only in non-speech tasks

Answer: (A)

The main idea is that sound distortions and substitutions differ by whether the target phoneme is kept or replaced. In distortions, the speaker aims for a specific phoneme but produces it with altered articulation, so the sound is warped or slurred yet still tied to the intended sound. For example, an attempt at /s/ might come out as a distorted, hissy or fricated version that's not a clean /s/ but is still recognizably related to that target. In substitutions, the speaker replaces the intended phoneme with a different one entirely, so the sound you hear is another phoneme altogether, like aiming for /s/ but producing /t/ instead.

Other choices miss this distinction: distortions aren’t limited to voicing errors, they’re about articulation quality; substitutions don’t imply improved articulation, they reflect replacing the phoneme with a different one; and distortions aren’t restricted to non-speech tasks, they occur in spoken language as part of AOS.