Voice characteristics in patients with nasal congestion and enlarged pharyngeal tonsils

Purpose: The purpose of this study was to investigate the voice characteristics in patients with nasal congestion and enlarged pharyngeal tonsils. Materials and Methods: Twenty-two children with an adenoidal-nasopharyngeal (AN) ratio of <0.5 and nasal cavity resistance of ≤0.25 Pa/cm³/s were assigned to the normal group. Twenty-five children with an AN ratio of <0.5 and nasal cavity resistance of ≥0.5 Pa/cm³/s were classified into the nasal congestion group. Nineteen children with an AN ratio of ≥0.63 and nasal cavity resistance of ≤0.25 Pa/cm³/s were defined as the enlarged pharyngeal tonsils group. The test sound /N/ has a characteristic antiformants (AF). The fourth formant (F4), the formant frequency, was calculated to relativize formant frequencies that vary with vocal tract length. The AF divided by F4 (AF/F4) was also calculated. Results: The group with enlarged pharyngeal tonsils had the largest AF/F4. The nasal breathing group had the next largest AF/F4, and the normal group had the smallest AF/F4. Conclusion: Stenosed vocal tracts with nasal congestion or enlarged pharyngeal tonsils showed an increased frequency due to obstruction of ventilation, and the AF/F4 ratio in the enlarged pharyngeal tonsils group was greater than that of the nasal congestion group. Voice analysis is a potential no-invasive method of distinguishing between nasal congestion and enlarged pharyngeal tonsils.