Praxis SLP Licensure Exam

What auditory change accompanies narrowing harmonic spacing in a vowel during narrowband spectrogram observation?

1. The vowel begins at a higher pitch and ends at a lower pitch

2. The vowel is a diphthong that shifts from front to back

3. The vowel begins at a lower pitch and ends at a higher pitch

4. The vowel is a diphthong that shifts from low to high

The correct answer is: The vowel begins at a higher pitch and ends at a lower pitch

Narrowing harmonic spacing in a vowel, as observed in a narrowband spectrogram, typically relates to the changes in pitch characteristics associated with the harmonic structure of the sound produced. When harmonic spacing narrows, it often indicates an increase in the fundamental frequency, which is perceived as a higher pitch at the onset of the vowel sound. This effect can lead to the vowel starting at a higher pitch and gradually moving to a lower pitch, creating a descending pitch contour. This phenomenon is consistent with the acoustics of vowel production where an increase in tension within the vocal cords often results in a higher fundamental frequency, thus giving the initial higher pitch. As the sound progresses, various factors such as vocal cord relaxation or changes in the resonance characteristics can lead to a lowering of pitch. Understanding this relationship helps in identifying how specific articulatory adjustments may affect the harmonic structure of a vowel, aiding in the analysis of speech sounds and their representation in spectrograms, which is particularly relevant for speech-language pathology and audiology studies.