What term describes when a child has not acquired certain phonemes by the expected age and shows patterns in speech errors?

The term that accurately describes when a child has not acquired certain phonemes by the expected age and demonstrates consistent patterns in speech errors is phonological processes. Phonological processes refer to the systematic patterns of sound production errors that typically occur in children's speech as they learn to speak. These patterns can include simplifying complex sounds or altering sounds in a way that reflects their developing understanding of phonetic rules.

In this context, a child exhibiting phonological processes is still in the process of mastering the rules of their language’s sound system. For instance, a child might substitute one sound for another (such as saying "wabbit" for "rabbit") or omit certain sounds altogether, reflecting a common developmental stage rather than a permanent impairment. Understanding phonological processes is key in assessing and providing effective interventions for children as they develop their speech and language skills.

The other terms mentioned, such as articulation disorders and language delays, refer to different aspects of speech and language development and do not specifically encompass the patterns of errors related to phoneme acquisition. Speech dysfluency pertains to disruptions in the flow of speech, such as stuttering, which is also distinct from the issues described in this question.