Which speech elements are often more affected in AOS?

• A. Vowels only
• B. Consonant clusters and complex sequences
• C. Prosody only
• D. Lexical semantics

Answer: (B)

In apraxia of speech, the struggle is in planning and sequencing the movements needed for speech, so the most challenging parts are the complex sequences that require precise timing across several articulators. Consonant clusters and other multi-phoneme sequences demand rapid, coordinated movements, which is why they tend to show the most prominent errors, substitutions, or distortions and can be accompanied by groping. Vowels, while they can be affected, usually involve less complex sequencing once the motor plan is formed, so their errors aren’t as pronounced as those seen with clusters. Lexical semantics isn’t about movement planning, so it’s typically not impaired in AOS, and prosody may vary but isn’t as consistently disrupted as the ability to produce cluster-rich sequences. Therefore, consonant clusters and complex sequences are the elements most often more affected.