Metallic Voice: Physiological and Acoustic Features

The metallic voice is usually confused with ring or nasality by singers and nontrained listeners. who are not used to perceptual vocal analysis. They believe a metallic voice results from a rise in fundamental frequency. A diagnostic error in this aspect may lead to lowering pitch, an incorrect procedure that Could Cause vocal overload and fatigue. The purpose of this article is to Study the quality of metallic voice considering the correlation between information of the physiological and acoustic plans, based on a perceptive consensual assumption. Fiberscopic video pharyngolaryngoscopy was performed on 21 professional singers while speaking vowel [e]-in normal and metallic modes to observe muscular movements and structural changes of the velopharynx, pharynx, and larynx. Vocal samples captured simultaneously to the fiberscopic examination were acoustically analyzed. Frequency and amplitude of the first four formants (F(1), F(2), F(3), and F(4)) were extracted by means of linear predictor coefficients (LPC) Spectrum and were statistically analyzed. Vocal tract adjustments such as velar lowering, pharyngeal wall narrowing, laryngeal rise, aryepiglottic, and lateral laryngeal constrictions were frequently found: there were no significant changes in frequency and amplitude of F(1) in the metallic voiced there were significant increases in amplitudes of F(2), F(3), and F(4) and in frequency for F, metallic Voice perceived as louder was correlated to an increase ill amplitude of F(3) and F(4). Physiological adjustments of velopharynx, pharynx, and larynx are combined in characterizing the metallic voice and can be acoustically related to changes in formant pattern.

Speech Evaluation After Palatal Augmentation in Patients Undergoing Glossectomy

Objective: To assess, in patients undergoing glossectomy, the influence of the palatal augmentation prosthesis on the speech intelligibility and acoustic spectrographic characteristics of the formants of oral vowels in Brazilian Portuguese, specifically the first 3 formants (F1 [/a,e,u/], F2 [/o,o,u/], and F3 [/a,o/]). Design: Speech evaluation with and without a palatal augmentation prosthesis using blinded randomized listener judgments. Setting: Tertiary referral center. Patients: Thirty-six patients (33 men and 3 women) aged 30 to 80 (mean [SD], 53.9 [10.5]) years underwent glossectomy (14, total glossectomy; 12, total glossectomy and partial mandibulectomy; 6, hemiglossectomy; and 4, subtotal glossectomy) with use of the augmentation prosthesis for at least 3 months before inclusion in the study. Main Outcome Measures: Spontaneous speech intel-ligibility (assessed by expert listeners using a 4-category scale) and spectrographic formants assessment. Results: We found a statistically significant improvement of spontaneous speech intelligibility and the average number of correctly identified syllables with the use of the prosthesis (P < .05). Statistically significant differences occurred for the F1 values of the vowels /a,e,u/; for F2 values, there was a significant difference of the vowels /o,o,u/; and for F3 values, there was a significant difference of the vowels la,61 (P < .001). Conclusions: The palatal augmentation prosthesis improved the intelligibility of spontaneous speech and syllables for patients who underwent glossectomy. It also increased the F2 and F3 values for all vowels and the F I values for the vowels /o,o,u/. This effect brought the values of many vowel formants closer to normal.