Throaty Voice Quality: Subglottal Pressure, Voice Source, and Formant Characteristics

"Throaty" voice quality has been regarded by voice pedagogues as undesired and even harmful. This study attempts to identify acoustic and physiological correlates of this quality. One male and one female subject read a text habitually and with a throaty voice quality. Oral pressure during p-occlusion was measured as an estimate of subglottal pressure. Long-term average spectrum analysis described the average spectrum characteristics. Sixteen syllables, perceptually evaluated with regard to throaty quality by five experts, were selected for analysis. Formant frequencies and voice source characteristics were measured by means of inverse filtering, and the vocal tract shape of the throaty and normal versions of the vowels [a,u,i,ae] of the male subject were recorded by magnetic resonance imaging. From this material, area functions were derived and their resonance frequencies were determined. The throaty versions of these four vowels all showed a pharynx that was narrower than in the habitually produced versions. To test the relevance of formant frequencies to perceived throaty quality, experts rated degree of throatiness in synthetic vowel samples, in which the measured formant frequency values of the subject were used. The main acoustic correlates of throatiness seemed to be an increase of F1, a decrease of F4, and in front vowels a decrease of F2, which presumably results from a narrowing of the pharynx. In the male subject, voice source parameters suggested a more hyperfunctional voice in throaty samples.     

Outcome of Resonant Voice Therapy for Female Teachers With Voice Disorders: Perceptual, Physiological, Acoustic, Aerodynamic, and Functional Measurements

Teachers have a high percentage of voice problems. For voice disordered teachers, resonant voice therapy is hypothesized to reduce voice problems. No research has been done on the physiological, acoustic, and aerodynamic effects of resonant voice therapy for school teachers. The purpose of this study is to investigate resonant voice therapy outcome from perceptual, physiological, acoustic, aerodynamic, and functional aspects for female teachers with voice disorders. A prospective study was designed for this research. The research subjects were 24 female teachers in Taipei. All subjects received resonant voice therapy in groups of 4 subjects, 90 minutes per session, and 1 session per week for 8 weeks. The outcome of resonant voice therapy was assessed from auditory perceptual judgment, videostroboscopic examination, acoustic measurements, aerodynamic measurements, and functional measurements before and after therapy. After therapy the severity of roughness, strain, monotone, resonance, hard attack, and glottal fry in auditory perceptual judgments, the severity of vocal fold pathology, mucosal wave, amplitude, and vocal fold closure in videostroboscopic examinations, phonation threshold pressure, and the score of physical scale in the Voice Handicap Index were significantly reduced. The speaking Fo, maximum range of speaking Fo, and maximum range of speaking intensity were significantly increased after therapy. No significant change was found in perturbation and breathiness measurements after therapy. Resonant voice therapy is effective for school teachers and is suggested as one of the therapy approaches in clinics for this population.     

Voice Therapy Outcome—A Randomized Clinical Trial Comparing Individual Voice Therapy,Therapy in Group,and Controls Without Therapy

ObjectiveA stumbling-block in voice therapy is how the patient will be able to apply the new voice technique in everyday life. Possibly this generalization process could be facilitated by giving voice therapy in group because of the natural forum for training voice-to-speech early in communication between the patients in a group setting. The aim of the study was to compare treatment results from individual voice therapy and voice therapy in group, at several time points and in comparison to patients with no voice therapy.MethodsA randomized treatment study was performed with 77 consecutive patients diagnosed with a functional voice disorder. Thirty-one patients were randomized to individual and group therapy, respectively, and 15 patients to no therapy. The assessments included standardized voice recording and registration of voice range profile (VRP), answering Voice handicap index (VHI) and visual analogue scales for self-hoarseness and self-vocal fatigue, and perceptual voice evaluation by speech-language pathologist. The assessments were performed before, direct after therapy, and three months later in all groups. The 2 therapy groups were also assessed 12 months after therapy.ResultsAll VHI scores as well as the self-ratings of hoarseness and vocal fatigue, and the perceptual evaluation of voice quality and maximum VRP improved significantly in both therapy groups 3 months after treatment and at 12 months follow-up. There were no significant changes in the control group, with the exception of decreased self-rated hoarseness and increased maximum VRP. Comparisons between treatment groups showed significant larger improvement after group therapy for VHI physical subscale at 12 months, as well as significant lower VHI total score at all measurement sessions and lower subscale scores at 12 months. There were no differences between treatment groups in self-hoarseness or self-vocal fatigue and no difference in perceptual voice quality or VRP. Comparison between controls and treatment groups showed significant larger change in treatment groups from baseline to three months in VHI total and to end of therapy in functional subscale. Treatment groups also showed significant lower scores than controls at each measurement session, for VHI total and physical subscale as well as lower degree of perceptual aberration of voice quality and vocal fatigue, at three months follow-up.ConclusionsThis study shows long-term improvement from behavioral voice therapy, particularly in a group setting. The results indicate the importance of early transfer-to-speech and late posttherapy test to capture whether the goal of voice therapy was fulfilled or not for the patients.     

Normative Voice Range Profiles of Male and Female Professional Voice Users

Normative voice range profiles (VRP) are calculated for a group of male and female teachers, based on 43 and 46 recordings, respectively. All individuals had healthy voices. These normative VRPs contain 95% prediction intervals for both frequency and intensity. They are based on a series of mathematical transformations of the original individual VRPs in order to maintain in the normative VRPs the typical oval VRP shape, including the dip between modal and falsetto register. The normative VRPs presented are directly applicable in the clinical practice of otolaryngologists and speech-language pathologists.