Objektiv gemessene Stimmlippenschwingungsirregularität vs. subjektiver Eindruck der Rauigkeit

Differences of Electroglottographical Contact Quotients between Connected Speech and Sustained Phonation in Clinical Measurement of Voice

INTRODUCTION

In clinical practice, sustained phonation is mostly used for acoustic voice measurements, while perceptual evaluation is based on connected speech. Since sustained phonation could be associated with the use of the singing voice, and since vocal registers are more relevant for singing rather than speech, it is unclear if vocal registers contribute to observable vocal fold contact differences between sustained phonation and speech.

MATERIAL AND METHODS

Sustained phonation (vowel [a] on comfortable pitch and loudness) and connected speech (German text: Der Nordwind und die Sonne) were analyzed for 1216 subjects (426 with and 790 without dysphonia) using the Laryngograph system (combining electroglottography and audio recordings). From these samples, fundamental frequency (ƒ_o), contact quotient (CQ), sound pressure level (SPL) and frequency perturbation (jitter first for sustained and cFx for connected speech) were evaluated.

RESULTS

Compared to connected speech, the values of ƒ_o and SPL were higher for sustained phonation. For female voices, ƒ_o difference was greater than for male voices. At the same time, and only for the females, CQ was lower for the sustained phonation, indicating a register difference.

CONCLUSION

In order to achieve a better comparability, sustained phonation should be standardized regarding the ƒ_o and SPL values in correspondence to the ƒ_o and SPL range of reading a text. This should also reduce the risk of using a different register for different types of phonation.

Automatic Evaluation of Voice Quality Using Text-Based Laryngograph Measurements and Prosodic Analysis

Due to low intra- and interrater reliability, perceptual voice evaluation should be supported by objective, automatic methods. In this study, text-based, computer-aided prosodic analysis and measurements of connected speech were combined in order to model perceptual evaluation of the German Roughness-Breathiness-Hoarseness (RBH) scheme. 58 connected speech samples (43 women and 15 men; 48.7 ± 17.8 years) containing the German version of the text "The North Wind and the Sun" were evaluated perceptually by 19 speech and voice therapy students according to the RBH scale. For the human-machine correlation, Support Vector Regression with measurements of the vocal fold cycle irregularities (CFx) and the closed phases of vocal fold vibration (CQx) of the Laryngograph and 33 features from a prosodic analysis module were used to model the listeners' ratings. The best human-machine results for roughness were obtained from a combination of six prosodic features and CFx (r = 0.71, ρ = 0.57). These correlations were approximately the same as the interrater agreement among human raters (r = 0.65, ρ = 0.61). CQx was one of the substantial features of the hoarseness model. For hoarseness and breathiness, the human-machine agreement was substantially lower. Nevertheless, the automatic analysis method can serve as the basis for a meaningful objective support for perceptual analysis.

Electrolaryngographic analysis in the diagnosis and phonosurgical treatment of benign laryngeal pathologies

The authors describe their use of electrolaryngographic (ELG) analysis in four clinical cases: vocal fold lesions (one case); two cases of disordered mobility; and a case with vocal fold structural anomalies. The value of ELG-based analysis is shown both in the description of the pathologies and in the evaluation of the results of surgery.

Hearing and phonetic criteria in voice measurement: clinical applications

Quantitative clinical voice analysis is discussed with special reference to four factors: 1) measurement criteria that are based on well established auditory parameters; 2) voice material that is modelled on the connected speech of ordinary spoken communication rather than sustained vowels; 3) direct monitoring so as to provide both acoustic and vocal fold contact signals; and 4) phonetic structural similarities across what are ordinarily regarded as highly dissimilar languages. These factors have motivated the development and clinical application of physical analyses that provide measurements related both to vocal fold function and to the perceptual attributes of pitch, loudness, and an important aspect of voice quality.

Electrical stimulation-supported voice exercises are superior to voice exercise therapy alone in patients with unilateral recurrent laryngeal nerve paresis: results from a prospective, randomized clinical trial

For more than 40 years, electrical stimulation procedures for unilateral recurrent laryngeal nerve paresis (URLNP) therapy have been proposed. However, it is unclear whether electrical stimulation therapy is effective for URLNP patients. In this study we compare the outcome of traditional voice exercise treatment (VE) with electrical stimulation-supported voice exercise (ES). A total of 90 URLNP patients were recruited to participate in a prospective, randomized trial. The decrease in vocal fold irregularity (CFx) and increase in maximum phonation time (MPT) after a 3-month therapy period were the dependent variables. In the ES group, CFx improved to a significantly greater extent than in the VE group. MPT increased similarly in both groups. Our data indicate that ES is superior to VE for patients with URLNP. Because no further data exist, it can be assumed that improvement following VE only reflects spontaneous recovery. However ES appears to be an effective non-surgical therapeutic procedure.

Electroglottography in elderly patients with vocal-fold palsy

The incidence of dysphonia in healthy elderly people is high. In individuals with iatrogenic vocal-fold paresis following thyroid surgery, serious aggravation of vocal skills contributes to impaired quality of life and requires proper management. Electroglottography is a common method for providing noninvasive measurements of glottal activity, yielding reliable indicators of glottal closing instants. The purpose of the study was to determine how electroglottography measures change with voice recovery in elderly speakers with vocal-fold palsy, compared with healthy elderly individuals, and which coefficient best represents dysphonia. An electroglottograph with Speech Studio 1.04 software was used to record and analyze the data. Electroglottography data were collected from 12 patients aged 65-78 years (mean=71.3, S.D.=3.8, median=71) and 10 healthy speakers aged 65-77 years (mean=70.9, S.D.=3.9, median=72). The findings show that the distribution of values of % irregularity differs between the groups of patients and controls. % Irregularity and closing quotient significantly correlate with the perceptual degree of dysphonia. Electroglottography can objectify dysphonia in elderly patients with vocal-fold palsy and is a suitable noninvasive tool for tracking the elderly patients' long-term progress. % Irregularity best represents the vocal-fold dysfunction in elderly patients with a vocal-fold palsy.