What term describes the difficulty in pronouncing correct sounds or substituting incorrect sounds?

The term that accurately describes the difficulty in pronouncing correct sounds or substituting incorrect sounds is articulation difficulties. This term refers specifically to challenges that individuals may face in the physical production of speech sounds. These difficulties can manifest in various ways, such as substituting one sound for another (for instance, saying "wabbit" instead of "rabbit") or omitting certain sounds altogether.

Articulation difficulties can arise from a range of factors, including developmental issues, hearing impairments, or structural issues with the mouth or vocal apparatus. Addressing these difficulties usually involves targeted speech therapy, where individuals receive help to improve their pronunciation and sound production.

The other terms listed pertain to different aspects of communication. Fluency disorders refer to interruptions in the flow of speech, such as stuttering. Voice disorders involve problems with the pitch, volume, or quality of voice rather than sound production. Expressive disorders, on the other hand, encompass broader difficulties in conveying thoughts and ideas effectively, which may involve language processing issues rather than purely articulation challenges.