Which characteristic defines vowels in speech?

• A. A closed vocal tract configuration
• B. The absence of vocal cord vibration
• C. An open vocal tract configuration
• D. The presence of nasal sounds

Answer: (C)

Vowels are characterized by an open vocal tract configuration, which allows for the unobstructed flow of air during their production. This open configuration leads to a range of resonant frequencies, creating the rich, full sounds associated with vowels. When producing a vowel, the articulators (such as the tongue and lips) modify the shape of the oral cavity without significantly blocking the airflow, which is essential for vowel quality and intelligibility.

In contrast, a closed vocal tract configuration would typically be associated with the production of consonants or specific sounds that require constriction or closure. The absence of vocal cord vibration refers to voiceless sounds, which can be consonants, but vowels are generally characterized by their voiced nature. Similarly, nasal sounds involve airflow through the nasal cavity and are not a defining feature of vowels, which primarily resonate in the oral cavity.