Herbal Medicine and Voice Quality: Uncovering the Impact Through Acoustic Analysis.

Objective: Rutarin, an herbal formulation combining powdered seeds of Cydonia oblonga (quince) and aerial parts of Origanum majorana (marjoram), is used to address respiratory issues and enhance voice quality. This study investigates the effects of Rutarin on voice parameters, including fundamental frequency (F0), jitter, shimmer, harmonics-to-noise ratio (HNR), cepstral peak prominence (CPP), and smoothed cepstral peak prominence (CPPS).

Methods: Voice samples of 79 individuals who produced a sustained vowel /a/ were examined before and after consuming either Rutarin or warm water. The pretest vowel production was performed twice with a 5-minute interval between the first and second recordings before the actual test. Following consumption, the post test was performed five times for each participant at intervals immediately after drinking, 5, 15, 35, and 60 minutes. The repeated measure analysis of variance and Friedman test were employed to assess the within-subject differences, allowing the analysis of multiple conditions experienced by the same individual.

Results: Despite the recognized medicinal properties of its components, Rutarin did not produce significant improvements in voice quality compared to water. Water demonstrated notable effects on F0, jitter, HNR, CPP, and CPPS, particularly in male participants (P < 0.05).

Conclusion: Although Rutarin may offer some therapeutic advantages for throat and respiratory health, it does not appear to enhance vocal performance as claimed.