[The Evaluation of Voice Quality via Signal Typing in Voice using Narrowband Spectrograms]. / Spektrografische Stimmtypenklassifizierung zur Beurteilung der Stimmqualität.

OBJECTIVE: Traditionally, voice quality is evaluated by auditory-perceptual judgment but objective-acoustic analyses are also valid tools. Spectrography is a part of objective-acoustic analyses and is used since around 50 years. Recently, Sprecher et al. (2010) designed a new classification scheme for signal typing in voice using narrowband spectrograms. The present study aimed to explore the external validation between these 2 methods in a larger dataset. MATERIALS AND METHODS: In total 300 voice samples were used based on the vowel [a:], in which n=270 had various degrees of dysphonia and n=30 were vocally normal. All voice samples were evaluated by 7 speech-language therapists using the RBH-scale and 2 judges analyzed the signal typing in voice using narrowband spectrograms. RESULTS: The intra- and inter-rater reliability of all RBH parameters was fair in average (kappa=0.234-0.383) but the rater reliability was moderate between the 2 judges rating signal typing in voice (kappa=0.457). A strong concurrent validity was identified between the signal typing in voice using narrowband spectrograms and auditory-perceptual judgment of hoarseness and breathiness (H: r=0.746, p=0.000; B: r=0.746, p=0.000) but only fair in roughness (r=0.370, p=0.000). CONCLUSION: The present results confirmed the results of Sprecher et al. (2010) and it might be meaningful to benefit signal typing in voice using narrowband spectrograms on sustained vowels as a valid complement in the evaluation of hoarseness and breathiness for clinical utility and research.

[Reliability and Validity of the "Voice Handicap Index (VHI) Adapted to the Singing Voice"]. / Reliabilität und Validität des "Voice Handicap Index (VHI) adaptiert an die Gesangsstimme".

BACKGROUND: The Voice Handicap Index (i. e., VHI) is one of the most reliable standardized self-evaluation assessments in diagnosis of voice disorders. That tool is the most used in daily clinic. In 2007, the VHI was adapted to the singing population, called 'VHI adapté aux chanteurs'. The aim of our study was to investigate the reliability and validity of the German version of the VHI adapted to the singing voice. MATERIALS AND METHODS: 113 German singers (41 males and 72 females) with diverse singing styles and profession were included in the study. They were divided into 2 groups: a test-group (n=20) with self-perceived vocal complaints and a control-group (n=93) without vocal complaints. Statistical analysis to measure the reliability and validity was conducted with the Cronbach's alpha (i. e., Cron. α), independent t-test and receiver operating characteristics as well likelihood ratio, respectively. RESULTS: Reliability was confirmed by acceptable Cron. α (0.713-0.850) for each of the sub-scales and total score. The validity between the 2 groups showed high significant differences for each of the sub-scales and total score by which the test-group indicated higher scores than the control-group. Only the construct validity revealed no clear results. CONCLUSION: The VHI adapted to the singing voice is suited as reliable and valid standardized evaluation tool, but the diagnostic accuracy has to be investigated again because of too high inaccuracy in the interpretation of the outcome of the present data.

[Test-retest variability and internal consistency of the Acoustic Voice Quality Index]. / Test-Retest-Variabilität und interne Konsistenz des Acoustic Voice Quality Index.

BACKGROUND: The aim of this study was to determine the test-retest variability of the Acoustic Voice Quality Index (AVQI) and to investigate the weighting of the test's two components (sustained vowel and continuous speech) with regards to the final AVQI score. PATIENTS AND METHODS: During this study, 43 test subjects with varying degrees of hoarseness were each assessed twice using the AVQI. RESULTS: No statistically significant differences were found between the end results of the two AVQI repetitions (t = 1.205; p = 0.235). The test-retest procedure outcome value of 0.54 confirms a low level of AVQI score variability. The end result of the AVQI assessment is most strongly influenced by sustained phonation of the vowel /a/ (r(2) = 0.88.). Although sustained phonation has a significantly greater influence on AVQI score than continuous speech (z = - 3.34; p < 0.01), the latter component also makes a substantial contribution to the final result (r(2) = 0.55). CONCLUSIONS: The results confirm a low level of test-retest variability within the AVQI. Combining the two speech elements showed a greater contribution of sustained vowel phonation to the final AVQI score.

[Effects of different tasks on determination of the speaking fundamental frequency]. / Einfluss verschiedener Methoden zur Bestimmung der mittleren Sprechstimmlage.

BACKGROUND: The aims of the study were to investigate the effects of different tasks on determination of the speaking fundamental frequency (SFF) using acoustic measurements and to formulate a tentative proposal based on the results of the current and other studies on this topic. METHODS: A total of 36 normophonic German subjects were examined. Nine different tasks commonly used in science and in clinical work for determination of the SFF were used. RESULTS: The maximum deviation in F0 across all methods was 18 Hz in women and 8 Hz in men. Women revealed significantly lower F0 values in spontaneous speech, reading, counting from both 1-10 and 1-60, as well as in the vowel [i:] and the "um Hm" utterances, when compared with the vowel [a:] using the procedure of Awan (p < 0.05). Furthermore, significantly lower F0 values were found in the reading and the picture storytelling task (p < 0.05). Men revealed significantly higher F0 values in spontaneous speech, reading and the picture storytelling task in comparison to the vowel [a:] and the counting tasks (p < 0.05). CONCLUSIONS: In line with findings of other recent studies, this study confirms the validity of the proposal that there is a significant difference in F0 values as it pertains to vowels, counting, and continuous speech. Thus, it follows that continuous speech should be used for determining the SFF.

[The Acoustic Voice Quality Index. Toward expanded measurement of dysphonia severity in German subjects]. / Der Acoustic Voice Quality Index in Deutsch. Ein Messverfahren zur allgemeinen Stimmqualität.

BACKGROUND: The purpose of this study was first to explore the cross-linguistic robustness of the Acoustic Voice Quality Index (i.e., AVQI) when administered to German continuous speech segments instead of Dutch sentences. The second aim was to define a normative AVQI threshold for distinguishing between normophonia and dysphonia in German speakers. METHODS: Sixty-one German subjects with diverse voice disorders were asked to sustain the vowel [a] and to read aloud a common text. A 3-s mid-vowel segment and the first two sentences of the text "The northwind and the sun" were edited, concatenated and analyzed according to methods described elsewhere. The voice recordings from all 61 participants were (1) auditory-perceptually rated with 'H' from the RBH system by five experienced clinicians and (2) acoustically analyzed to yield the AVQI scores. RESULTS: First, a reasonable correlation was found between the AVQI and H (i.e., r(s) = 0.79). Second, the AVQI revealed an acceptable diagnostic differentiation between normal and dysphonic voices (i.e., AUC = 0.888). These results on German material accord with the results from previous studies on Dutch material. Furthermore, in the German version, the AVQI's cutoff score of 2.70 is accompanied by sensitivity = 79% and specificity = 92%. This indicates minimal normative deviation from the AVQI's cutoff score of 2.95 in Dutch. CONCLUSION: The present and the previous studies yielded almost identical results, denoting the AVQI's cross-linguistic robustness and its feasibility to clinically measure voice quality in German.