Acoustic Parameters of Perceptually Normal Voice Production in Filipinos: An Exploratory Study Among Selected Adults in Metro Manila

Abstract

Background and Objectives: Acoustic analysis is an objective instrumental method that makes more accurate and reliable assessments of vocal characteristics possible. The aim of the current study was to describe the vocal characteristics of Filipinos with perceptually normal voices in terms of (1) fundamental frequency, (2) intensity, (3) frequency and intensity perturbations, (4) speaking fundamental frequency range, and (5) nasalance.

Methodology: A total of 142 healthy adults aged 18 – 53 years participated in this study. The group was composed of 73 men (26.9 ± 6.4 years old) and 69 women (26.1 ± 6.5 years old). Voice samples were collected using Computerized SpeechLaboratoryTM (CSL; Model 4300B) during sustained phonation of vowel /a/ and spontaneous speech. NasometerTM (Model 6200-3) was used to assess nasality while participants read plosive and sibilant-loaded sentences.

Results and Conclusion: The average acoustic values for males were F₀ = 125.8 ± 23.4 Hz, SF₀ = 122.6 ± 15.6 Hz, SF₀ range = 85.8-269 Hz, SPL (speech) = 58.6 ± 5.3 dB, SPL (vowel) = 66.6 ± 6.2 dB, jitter = 0.92 ± 0.48%, shimmer = 2.21 ± 0.73%, nasalance = 12.5-17.1%; for females, F₀ = 196.3 ± 23.0 Hz, SF₀ = 194.8 ± 19.0 Hz, SF₀ range = 97.1-309.6Hz, SPL (speech) = 57.6 ± 4.3 dB, SPL (vowel) = 65.3 ± 4.5 dB, jitter = 1.12 ± 0.34%, shimmer = 2.7 ± 0.64%, nasalance = 13.1-19.1%. Significant differences were found between male and female subjects for F₀, SF₀, perturbation measures, and SPL during sustained phonation (p< 0.05). Acoustic data obtained also appear to be consistent with the results of local and international studies. While these can be used as tentative normative data for Filipinos, it is recommended that future studies be completed with more systematic analysis procedures and stringent participant selection to ensure balance for age, sex, and vocal history among subgroups.