Inter-device reliability of DSI measurement

T1a Glottic Cancer: Advances in Vocal Outcome Assessment after Transoral CO2-Laser Microsurgery Using the VEM

Patients with unilateral vocal fold cancer (T1a) have a favorable prognosis. In addition to the oncological results of CO₂ transoral laser microsurgery (TOLMS), voice function is among the outcome measures. Previous early glottic cancer studies have reported voice function in patients grouped into combined T stages (Tis, T1, T2) and merged cordectomy types (lesser- vs. larger-extent cordectomies). Some authors have questioned the value of objective vocal parameters. Therefore, the purpose of this exploratory prospective study was to investigate TOLMS-associated oncological and vocal outcomes in 60 T1a patients, applying the ELS protocols for cordectomy classification and voice assessment. Pre- and postoperative voice function analysis included: Vocal Extent Measure (VEM), Dysphonia Severity Index (DSI), auditory-perceptual assessment (GRB), and 9-item Voice Handicap Index (VHI-9i). Altogether, 51 subjects (43 male, eight female, mean age 65 years) completed the study. The 5-year recurrence-free, overall, and disease-specific survival rates (Kaplan–Meier method) were 71.4%, 94.4%, and 100.0%. Voice function was preserved; the objective parameter VEM (64 ± 33 vs. 83 ± 31; mean ± SD) and subjective vocal measures (G: 1.9 ± 0.7 vs. 1.3 ± 0.7; VHI-9i: 18 ± 8 vs. 9 ± 9) even improved significantly (p < 0.001). The VEM best reflected self-perceived voice impairment. It represents a sensitive measure of voice function for quantification of vocal performance.

Monitoring the Outcome of Phonosurgery and Vocal Exercises with Established and New Diagnostic Tools

Instrument-assisted measuring procedures expand the options within phoniatric diagnostics by quantifying the condition of the voice. The aim of this study was to examine objective treatment-associated changes of the recently developed vocal extent measure (VEM) and the established dysphonia severity index (DSI) in relation to subjective tools, i.e., self-evaluation via voice handicap index (VHI-12) and external evaluation via auditory-perceptual assessment of hoarseness (H). The findings for H (3 raters' group assessment), VHI-12, DSI, and VEM in 152 patients of both sexes (age range 16–75 years), taken before and 3 months after phonosurgery or vocal exercises, were compared and correlated. Posttherapeutically, all of the recorded parameters improved (p < 0.001). The degree of H reduced on average by 0.5, the VHI-12 score sank by 5 points, while DSI and VEM rose by 1.5 and 19, respectively. The correlations of these changes were significant but showed gradual differences between H and VHI-12 (r = 0.3), H and DSI (r = −0.3), and H and VEM (r = −0.4). We conclude that all investigated parameters are adequate to verify therapeutic outcomes but represent different dimensions of the voice. However, changes in the degree of H as gold standard were best recognized with the new VEM.

Validation of the Dysphonia Severity Index in the Dr. Speech Program

PURPOSE

The Dysphonia Severity Index (DSI) is an objective multiparameter index of voice quality that measures and describes overall voice quality. Some studies have suggested that the reliability of devices for DSI measurement should be examined. We explored the feasibility of DSI measurements using the Dr. Speech (DRS) device, verified its effectiveness for clinical voice measurements and intradevice reliability, and examined the correlation between the DSI and self-evaluations of voice problems.

METHODS

Seventy adult participants (including individuals with voice problems and healthy adults) underwent objective and subjective voice assessments. These data were then used to establish a DSI_DRS model and test the intradevice (DRS device and Praat software) reliability. The clinical validation of the DSI_DRS was conducted by measuring the DSI of six other participants and comparing the observed and predicted perceived voice quality as expressed by the G score (of the GRBAS scale). Moreover, the relationship between the DSI measurements and participants' self-evaluations of voice problems was investigated by analyzing the correlation between the DSI and the Voice Handicap Index (VHI).

RESULTS

The DSI_DRS discriminated 80% of participants' voice quality ratings. There were strong correlations between the DSI and variables measured by the DRS device and Praat software. Furthermore, there was no significant correlation between the DSI_DRS and VHI.

CONCLUSION

The DRS device can perform DSI measurements. Objective voice measurements and perceptual voice ratings reflected different aspects of vocal function and its effects. These factors should be considered in clinical practice settings.

Gender-specific reference ranges of the vocal extent measure in young and healthy adults

Objective: The recently developed vocal extent measure (VEM) quantifies a patient's vocal capacity as documented in the voice range profile (VRP). This study presents the first reference ranges of the VEM for young subjects without voice complaints. Furthermore, this study investigates the influence of gender on the VEM as well as the correlation of the VEM with the dysphonia severity index (DSI).Patients and methods: Reference ranges were captured by combining a retrospective analysis of subjects who received a medical fitness certificate of a healthy voice (n = 135) and a prospective analysis of adult volunteers without voice complaints (n = 67). Every participant obtained a standardized voice assessment comprising videolaryngostroboscopy, auditory-perceptual analysis, acoustic analysis, VRP, and the Voice Handicap Index (VHI-9i).Results: A total of 202 subjects were recruited and investigated. Due to our stringent selection criteria, 51 participants had to be excluded from further analysis. The remaining data of 151 participants (52 males, 99 females), aged 18-39 years (mean 24, SD 5), were analysed in more detail. The mean of the VEM amounted to 123.7 (SD 12.6) for males and 114.4 (SD 13.3) for females. The values differed significantly between both sexes and correlated significantly with the corresponding DSI values.Conclusion: By introducing the first reference values, this study represents the next step of implementing the VEM in daily phoniatric diagnostics. These values serve as a basis to interpret the VEM regarding the degree of severity of voice disorders and to evaluate treatment success.

Efficacy of microsurgery in Reinke's oedema evaluated by traditional voice assessment integrated with the Vocal Extent Measure (VEM)

SUMMARY

There are few data analysing to what specific extent phonomicrosurgery improves vocal function in patients suffering from Reinke's oedema (RE). The recently introduced parameter vocal extent measure (VEM) seems to be suitable to objectively quantify vocal performance. The purpose of this clinical prospective study was to investigate the outcomes of phonomicrosurgery in 60 RE patients (6 male, 54 female; 56 ± 8 years ([mean ± SD]) by analysing its effect on subjective and objective vocal parameters with particular regard to VEM. Treatment efficacy was evaluated at three months after surgery by comparing pre- and postoperative videolaryngostroboscopy (VLS), auditory-perceptual assessment (RBH-status), voice range profile (VRP), acoustic-aerodynamic analysis and patient's self-assessment using the voice handicap index (VHI-9i). Phonomicrosurgically, all RE were carefully ablated. VLS revealed removal or substantial reduction of oedema with restored periodic vocal fold vibration. All subjective and most objective acoustic and aerodynamic parameters significantly improved. The VEM increased on average from 64 ± 37 to 88 ± 25 (p #x003C; 0.001) and the dysphonia severity index (DSI) from 0.5 ± 3.4 to 2.9 ± 1.9. Both parameters correlated significantly with each other (rs = 0.70). RBH-status revealed less roughness, breathiness and overall grade of hoarseness (2.0 ± 0.7 vs 1.3 ± 0.7). The VHI-9i-score decreased from 18 ± 8 to 12 ± 9 points. The average total vocal range enlarged by 4 ± 7 semitones, and the mean speaking pitch rose by 2 ± 4 semitones. These results confirm that: (1) the use of VEM in RE patients objectifies and quantifies their vocal capacity as documented in the VRP, and (2) phonomicrosurgery is an effective, objectively and subjectively satisfactory therapy to improve voice in RE patients.

Diagnostic Accuracy of Dysphonia Classification of DSI and AVQI

OBJECTIVE

The Dysphonia Severity Index (DSI) and the Acoustic Voice Quality Index (AVQI) have been successfully investigated to quantify voice quality. The aim of the present study was to evaluate the diagnostic accuracy of both measurements in comparison with the dysphonia classification.

METHODS

In total, 264 subjects with vocally healthy voices (n = 105) and with various voice disorders (n = 159) were included in the study. To determine the dysphonia classification, all subjects underwent a videolaryngostroboscopy and, if necessary, a direct microlaryngoscopy plus a clinical examination to diagnose a voice disorder. Patients with a vocally healthy voice had no actual voice complaints, no history of chronic laryngeal diseases or voice disorders, no hearing problems and were determined as healthy voices by clinical voice specialists. To evaluate the diagnostic accuracy, receiver operating characteristic statistics and correct classification rate (CCR) were used.

RESULTS

The diagnostic accuracy of DSI and AVQI showed strong sensitivity and specificity in the determination of dysphonia classification. A DSI threshold of 3.05 obtained a high sensitivity of 94.3% and specificity of 84.3%. An CCR of 88% was determined for DSI. Also, an AVQI threshold of 3.31 showed reasonable sensitivity of 71.7% and specificity of 88%. The CCR for AVQI was 79%.

CONCLUSION

Although DSI and AVQI were developed to quantify voice quality, the present results showed that both measurements can evaluate the dysphonia classification as well. Particularly, the DSI might have higher potential in the evaluation of dysphonia classification.

LEVEL OF EVIDENCE

2C Laryngoscope, 129:692-698, 2019.

Efficacy of Phonosurgery, Logopedic Voice Treatment and Vocal Pedagogy in Common Voice Problems of Singers

INTRODUCTION

Functional and organic impairments of the singing voice are common career-threatening problems of singers presenting in phoniatric and laryngological departments. The objective was to evaluate the efficacy of phonosurgery, logopedic voice treatment and vocal pedagogy in common organic and functional voice problems of singers, including investigation of the recently introduced parameter vocal extent measure (VEM).

METHODS

In a prospective clinical study, the analysis of treatment outcome in 76 singers [57 female, 19 male; 38 ± 11 years (mean ± SD)] was based on pre- and post-therapeutic voice function diagnostics and videolaryngostroboscopy. Examination instruments included auditory-perceptual voice assessment, voice range profile (VRP), the VEM calculated from area and shape of the VRP, acoustic-aerodynamic analysis, and patients' self-assessment (e.g., Singing Voice Handicap Index).

RESULTS

While 28% of all singers (21/76) presented with functional dysphonia, 72% (55/76) were diagnosed with organic vocal fold changes, of which marginal edema (n = 25), nodules (n = 9), and polyps (n = 8) were the most common pathologic changes. Of the 76 singers, 57% (43) received phonosurgery, 43% (33) had conservative pedagogic (14) and logopedic (19) treatment. Three months post-therapeutically, most parameters had significantly improved. The dysphonia severity index (DSI) increased on average from 6.1 ± 2.0 to 7.4 ± 1.8 (p < 0.001), and the VEM from 113 ± 20 to 124 ± 14 (p < 0.001). Both parameters correlated significantly with each other (r_s = 0.41). Phonosurgery had the largest impact on the improvement of vocal function. Conservative therapies provided smaller quantitative enhancements but also qualitative vocal restoration with recovered artistic capabilities.

CONCLUSIONS

Depending on individual medical indication, phonosurgery, logopedic treatment and voice teaching are all effective, objectively and subjectively satisfactory therapies to improve the impaired singing voice. The use of VEM in singers with functional and organic dysphonia objectifies and quantifies their vocal capacity as documented in the VRP. Complementing the established DSI, VEM introduction into practical objective voice diagnostics is appropriate and desirable especially for the treatment of singers.

Tutorial and Guidelines on Measurement of Sound Pressure Level in Voice and Speech

PURPOSE

Sound pressure level (SPL) measurement of voice and speech is often considered a trivial matter, but the measured levels are often reported incorrectly or incompletely, making them difficult to compare among various studies. This article aims at explaining the fundamental principles behind these measurements and providing guidelines to improve their accuracy and reproducibility.

METHOD

Basic information is put together from standards, technical, voice and speech literature, and practical experience of the authors and is explained for nontechnical readers.

RESULTS

Variation of SPL with distance, sound level meters and their accuracy, frequency and time weightings, and background noise topics are reviewed. Several calibration procedures for SPL measurements are described for stand-mounted and head-mounted microphones.

CONCLUSIONS

SPL of voice and speech should be reported together with the mouth-to-microphone distance so that the levels can be related to vocal power. Sound level measurement settings (i.e., frequency weighting and time weighting/averaging) should always be specified. Classified sound level meters should be used to assure measurement accuracy. Head-mounted microphones placed at the proximity of the mouth improve signal-to-noise ratio and can be taken advantage of for voice SPL measurements when calibrated. Background noise levels should be reported besides the sound levels of voice and speech.

The Vocal Extent Measure: Development of a Novel Parameter in Voice Diagnostics and Initial Clinical Experience

Voice range profile (VRP) and evaluation using the dysphonia severity index (DSI) represent essentials of instrument-based objective voice diagnostics and are implemented in different standardized registration programs. The respective measurement results, however, show differences. The aim of the study was to prove these differences statistically and to develop a new parameter, the Vocal Extent Measure (VEM), which is not influenced by the measurement program. VRPs of 97 subjects were recorded by two examiners using the established registration programs DiVAS (XION medical) and LingWAVES (WEVOSYS) simultaneously. The VEM was developed on the basis of VRP area and perimeter. All 194 VRP files were analyzed for various parameters and gender independence. The registration programs exhibited significant differences in several vocal parameters. A significant gender influence for DSI was found with DiVAS (p < 0.01), but not with LingWAVES. The VEM quantified the dynamic performance and frequency range by a unidimensional, interval-scaled value without unit, mostly between 0 and 120. This novel parameter represents an intelligible and user-friendly positive measure of vocal function, allows simple and stable VRP description, and seems to be suitable for quantification of vocal capacity. In contrast to DSI, the VEM proved to be less susceptible to registration program and gender.

The Use of Sound Level Meter Apps in the Clinical Setting

PURPOSE

The purpose of this study was to compare sound level meter (SLM) readings obtained using a Larson-Davis (Depew, NY) Model 831 Type 1 SLM, a RadioShack (Fort Worth, TX) SLM, and iPhone 5 (Apple, Cupertino, CA) SLM apps.

METHOD

In Procedure 1, pure tones were measured in an anechoic chamber (125, 250, 500, 1000, 2000, 4000, and 8000 Hz); sound pressure levels (SPLs) ranged from 60 to 100 dB SPL in 10-dB increments. In Procedure 2, human voices were measured. Participants were 20 vocally healthy adults (7 women, 13 men; mean age = 25.1 years). The task was to sustain a vowel "ah" at 3 intensity levels: soft, habitual, and loud. Microphones were lined up equal distances from the participant's mouth, and recordings were captured simultaneously.

RESULTS

Overall, the 3 SLM apps and the RadioShack SLM yielded inconsistent readings compared with the Type 1 SLM.

CONCLUSION

The use of apps for SPL readings in the clinical setting is premature because all 3 apps adopted were incomparable with the Type 1 SLM.

The softest sound levels of the human voice in normal subjects

Accurate measurement of the softest sound levels of phonation presents technical and methodological challenges. This study aimed at (1) reliably obtaining normative data on sustained softest sound levels for the vowel [a:] at comfortable pitch; (2) comparing the results for different frequency and time weighting methods; and (3) refining the Union of European Phoniatricians' recommendation on allowed background noise levels for scientific and equipment manufacturers' purposes. Eighty healthy untrained participants (40 females, 40 males) were investigated in quiet rooms using a head-mounted microphone and a sound level meter at 30 cm distance. The one-second-equivalent sound levels were more stable and more representative for evaluating the softest sustained phonations than the fast-time-weighted levels. At 30 cm, these levels were in the range of 48-61 dB(C)/41-53 dB(A) for females and 49 - 64 dB(C)/35-53 dB(A) for males (5% to 95% quantile range). These ranges may serve as reference data in evaluating vocal normality. In order to reach a signal-to-noise ratio of at least 10 dB for more than 95% of the normal population, the background noise should be below 25 dB(A) and 38 dB(C), respectively, for the softest phonation measurements at 30 cm distance. For the A-weighting, this is 15 dB lower than the previously recommended value.