Praxis SLP Licensure Exam

How do obstruent sounds differ from resonant sounds?

1. They always include a quasi-periodic sound source

2. They always include an aperiodic sound source

3. They are always continuant

4. They are always noncontinuant sounds

The correct answer is: They always include an aperiodic sound source

Obstruent sounds differ from resonant sounds primarily by the presence of an aperiodic sound source. Obstruent sounds, which include stops, fricatives, and affricates, are characterized by a significant constriction or blockage in the vocal tract that leads to turbulent airflow. This turbulence produces noise that is typically aperiodic, meaning it does not have a regular periodic waveform. In contrast, resonant sounds, which encompass vowels and some consonants (like nasals and approximants), are produced without significant constriction and often have a more periodic sound source, resulting in a clearer tonal quality. While certain sounds can have complex sound sources, the defining characteristic that separates obstruents from resonants is the presence of the aperiodic sound source in obstruents, leading to a different auditory perception. This distinction is fundamental in phonetics and phonology, affecting how sounds are classified and analyzed.