Relative Fundamental Frequency of Female Speakers by Korean Consonant Types

Objectives: Relative fundamental frequency (RFF) is an acoustic measure reflecting laryngeal tension during the transition between voiced and voiceless segments. Although extensively studied in English, little is known about its applicability to Korean, which features unique laryngeal contrasts (lenis, tense, aspirated). This study aimed to examine whether RFF patterns in Korean parallel those in English and to identify the most suitable consonant contexts for reliable measurement. Methods: Participants included 10 healthy young adult females with normal voices. Speech materials consisted of /VCV/ sequences incorporating Korean tense and aspirated stops, affricates, and fricatives. Recordings were analyzed using Praat following established RFF procedures. Mean RFF values and standard deviations across Offset (cycles 1–10) and Onset (cycles 1–10) were calculated. Two-way repeated-measures ANOVAs were conducted to evaluate effects of consonant type and vocal cycle. Results: Results showed that Offset cycles generally decreased below 0 semitones (ST), while Onset cycles increased above 0 ST, replicating RFF patterns observed in English. No significant consonant-type differences emerged in Offset cycles; however, Onset cycles revealed significantly higher RFF for tense fricatives ([s*]) compared to stops and affricates. Stops tended to show lower variability than other consonants. Conclusion: These findings suggest that RFF patterns are physiologically comparable across English and Korean, supporting the cross-linguistic validity of RFF as an objective index of laryngeal tension. Particularly, the tense fricative [s*] may serve as an optimal consonant for Korean RFF measurement. Further research including different vowels, age groups, and disordered voices is warranted to standardize RFF protocols in Korean clinical contexts.