What type of error is characterized by substituting one sound for another in verbal apraxia?

In verbal apraxia, substituting one sound for another is a hallmark characteristic of the condition. This type of error is referred to as a substitution error, where a speaker replaces a target phoneme with an incorrect one during speech production. For example, instead of saying "cat," a person may produce "bat," demonstrating the incorrect substitution of the initial consonant sound. This phenomenon occurs due to difficulties in planning and coordinating the precise movements required for speech, rather than a lack of knowledge of the correct sounds.

Substitution errors highlight the speech planning aspect of verbal apraxia, distinguishing it from other types of errors such as deletions, omissions, or distortions, which involve different mechanisms in speech production. Understanding substitution errors is crucial for speech-language pathologists in diagnosing and treating apraxia effectively.