What vocal quality is described as hypo or hypernasal?

The term that describes vocal quality as hypo or hypernasal pertains to resonance disorders. This is because resonance refers to the quality of the sound generated by the vocal cords and how it is modified by the cavities within the vocal tract, including the throat, mouth, and nasal passages.

When someone experiences hypernasality, there is an excessive flow of air through the nasal cavity during speech, which can make sounds overly resonant, often perceived as a "nasal" quality. Conversely, hyponasality occurs when there is insufficient airflow through the nasal cavity, leading to a lack of resonance and making speech sound "stuffy" or muffled. These variations in resonance directly affect the clarity and quality of a person’s speech.

Fluency disorders, articulation disorders, and syllable timing disorders involve different aspects of speech production that are unrelated to vocal resonance. Fluency disorders focus on the flow of speech, articulation disorders involve the physical production of sounds, and syllable timing disorders relate to rhythm and pacing in speech, rather than the quality of voice that is affected by nasal airflow. Hence, resonance disorders are the appropriate category for the vocal quality described.