Final answer:
The correct option is (a). straw is not an effective method for assessing hypernasality, nasal emission, or velopharyngeal function. Instead, assessments are typically done using tools like listening tubes, stethoscopes, and manometers.
Step-by-step explanation:
The assessment of hypernasality, nasal emission, and velopharyngeal function is crucial for understanding and treating speech disorders. Tools such as a listening tube, stethoscope, and manometer can be used effectively in this assessment.
A listening tube helps by channeling the sound directly to the listener, providing a clearer indication of nasality. A manometer can measure the pressure during speech, indicating problems with velopharyngeal closure. A stethoscope amplifies internal body sounds, such as those associated with velopharyngeal insufficiency or nasal emission. However, using a straw is not an effective method for assessing these speech functions and therefore, it is not a suitable tool for this purpose. A straw would not provide any diagnostic information regarding these specific speech functions.