The described consonant inventory and substitutions in the 4 1/2-year-old child most strongly indicate which condition?

• A. Childhood apraxia of speech
• B. An oral motor impairment
• C. Delayed phonological development
• D. A significant high-frequency hearing loss

Answer: (C)

The key idea is that this child’s consonant system is simply lagging behind typical development, with substitutions that reflect an immature phonological system rather than a motor or perceptual problem. When a preschooler shows a limited consonant inventory and substitutions that match earlier developmental stages (for example, using simpler sounds in place of more complex ones, or reducing clusters), it points to a phonological delay—the sound system will usually catch up with time and targeted support. This pattern differs from a motor speech issue, where errors are often inconsistent, highly irregular, and accompanied by struggles with planning or sequencing the movements themselves. It also doesn’t fit a typical profile of significant high-frequency hearing loss, which would produce broader, perception-based gaps across sounds that depend on auditory discrimination. So the described inventory and substitutions align best with delayed phonological development, meaning the child’s speech problems are developmental and likely to improve as the child’s phonological system matures.