Individuals who have difficulty opening the velo-pharyngeal port may struggle to accurately produce which of the following sounds?

Individuals who have difficulty opening the velopharyngeal port may struggle to accurately produce nasal sounds, which include /m/. The velopharyngeal port is the space between the back of the throat and the soft palate, and when it opens, it allows airflow to go into the nasal cavity. For nasal consonants like /m/, this airflow is crucial.

When the velopharyngeal port does not open properly, it can lead to nasal obstruction, resulting in a substitution of sounds or difficulty producing them altogether. This barrier means that sounds that rely on nasal resonance, like /m/, will not be produced clearly or correctly due to inadequate airflow through the nasal passages.

In contrast, other sounds, like /b/, /k/, and /s/, do not require the velopharyngeal port to be open for their production. These sounds are created using different articulatory mechanisms that do not involve the nasal cavity in the same way as /m/. Therefore, the struggle with producing /m/ highlights the importance of the velopharyngeal function in speech production related to nasal sounds.