The improvement of internal consistency of the Acoustic Voice Quality Index.

PURPOSE: This investigation aims to explore the improvement of the relatively new hoarseness severity quantification method, called Acoustic Voice Quality Index (AVQI), which measures the concatenation of continuous speech (CS) and sustained phonation (SP) segments. Earlier investigations indicated that the proportion of the SP is more dominant in the final AVQI result than the CS. METHOD: Sixty voice samples were selected with different voice pathologies and equal distribution of hoarseness severity ranged from normal to severe. Every voice sample varied in three different durations: voice duration-one (VD-1) with seventeen syllables text plus three seconds of SP, voice duration-two (VD-2) with customized length of CS plus three seconds of SP, and voice duration-three (VD-3) with a whole text plus three seconds SP. All voice samples were perceptually judged on overall voice quality by five experienced voice clinicians. AVQI's precision and concurrent validity were assessed in all three VDs. Finally, the internal consistency across all three VDs was analyzed. RESULTS: No significant differences were found in the perceptual evaluation of overall voice quality across all three VDs by acceptable rater reliability. The concurrent validity distinguished in all three VDs as a marked degree of correlation (i.e., ranged from rs=0.891 to rs=0.929) with no significant differences across all three VDs. The best precision was found in VD-2. Finally, the internal consistency showed in VD-2 a balanced out impact of the final AVQI score with no significant differences from both speech tasks. CONCLUSION: Although AVQI currently uses the speech material of VD-1, the present study demonstrated the best results in VD-2 (i.e., precision and internal consistency). These features of VD-2 facilitate higher representativity and improve the validity of this objective diagnostic instrument.

The value of the acoustic voice quality index as a measure of dysphonia severity in subjects speaking different languages.

The Acoustic Voice Quality Index (AVQI) is a relatively new clinical method to quantify dysphonia severity. Since it partially relies on continuous speech, its performance may vary with voice-related phonetic differences and thus across languages. The present investigation therefore assessed the AVQI's performance in English, Dutch, German, and French. Fifty subjects were recorded reading sentences in the four languages, as well as producing a sustained vowel. These recordings were later edited to calculate the AVQI. The samples were also perceptually rated on overall dysphonia severity by three experienced voice clinicians. The AVQI's cross-linguistic concurrent validity and diagnostic precision were assessed. The results support earlier data, and confirm good cross-linguistic validity and diagnostic accuracy. Although no statistical differences were observed between languages, the AVQI performed better in English and German and less well in French. These results validate the AVQI as a potentially robust and objective dysphonia severity measure across languages.

The Influence of Voice Sample Length in the Auditory-Perceptual Judgment of Overall Voice Quality.

OBJECTIVES: The aim of this study was to explore the influence of voice sample lengths (VSLs) on the perceived degree of severity of overall voice quality. To increase a valid judgment in voice quality, a consistent rating is essential to estimate the presence and degree of severity of a voice. METHODS: Three VSLs were defined by varying only the length of continuous speech followed by constant duration of 3 seconds of the mid-vowel portion sustained vowel [a:]. VSL-1 contained 17 syllables as is used for the Acoustic Voice Quality Index by Maryn et al (2010). VSL-2 consisted of a customized length (ie, with a mean number of 35.5 syllables of the original text, which corresponds to 3 seconds of only-voiced segments in continuous speech). VSL-3 had 93 syllables, which represent a complete phonetically balanced text. An expert panel of five judges rated 100 voice samples with various degrees of hoarseness. In total, three sessions were achieved judging one VSL variant in one session of the 100 voice samples. RESULTS: The results showed significant differences of auditory-perceptual judgment between VSL-1 and VSL-2 (U = -4.985, P = 0.000), and between VSL-1 and VSL-3 (U = -5.642, P = 0.000). However, judgments of VSL-2 and VSL-3 did not differ significantly (U = -1.785, P = 0.074). CONCLUSION: Based on these results, it can be concluded that the judgment of VSL-2 is comparable with the judgment of VSL-3. Therefore, speech material for clinical judgment can be reduced to VSL-2 for rating overall voice quality.

Lax Vox as a Voice Training Program for Teachers: A Pilot Study.

OBJECTIVES: The objective of this study was to explore the effectiveness of a 3-week training program with the voice therapy "Lax Vox" for teachers. METHODS: Four healthy female teachers participated as volunteers for the study. Several voice measurements of perception, acoustics, aerodynamics, and self-evaluation were investigated. Furthermore, a survey to rate the applicability of Lax Vox was also part of the study. To assess the treatment effects of the Lax Vox training, an effect size analysis (dunb) was conducted. RESULTS: After 3 weeks of training, medium and large improvements were found in some parameters of perceptual and acoustic voice quality assessments (dunb >0.50 and dunb >0.80, respectively). Furthermore, medium improvements were revealed in some parameters of self-evaluation (ie, physical and total scale of the Voice Handicap Index) and aerodynamic (ie, maximum phonation time) assessments (all dunb >0.50). Additionally, acoustic measures of vocal function showed an expansion in the upper contour of voice range profiles after training. Particularly, the main improvements in the voice range profile was found in the modal and the beginning of the falsetto voice registers. There was an increase of the intensity levels of about 4.6 dB. No changes were revealed in some acoustic measures of the voice range profile, self-evaluation measurements, and the perception of breathy voice quality (all dunb <0.20). Finally, the applicability of Lax Vox perceptually showed clear support in training success, learning process, and transfer to the daily routine. CONCLUSIONS: Lax Vox training for teachers appears to improve select measures of voice quality, maximum phonation time, vocal function, self-evaluation, and perceived applicability.

Validation of the Acoustic Voice Quality Index in the Lithuanian Language.

OBJECTIVES: The aim of the present study was to validate the Acoustic Voice Quality Index in Lithuanian language (AVQI-LT) and investigate the feasibility and robustness of its diagnostic accuracy, differentiating normal and dysphonic voice. METHODS: A total of 184 native Lithuanian subjects with normal voices (n = 46) and with various voice disorders (n = 138) were asked to read aloud the Lithuanian text and to sustain the vowel /a/. A sentence with 13 syllables and a 3-second midvowel portion of the sustained vowel were edited. Both speech tasks were concatenated, and perceptually rated for dysphonia severity by five voice clinicians. They rated the Grade (G) from the Grade Roughness Breathiness Asthenia Strain (GRBAS) protocol and the overall severity from the Consensus Auditory-perceptual Evaluation of Voice protocol with a visual analog scale (VAS). The average scores (Gmean and VASmean) were taken as the perceptual dysphonia severity level for every voice sample. All concatenated voice samples were acoustically analyzed to receive an AVQI-LT score. RESULTS: Both auditory-perceptual judgment procedures showed sufficient strength of agreement between five raters. The results achieved significant and marked concurrent validity between both auditory-perceptual judgment procedures and AVQI-LT. The diagnostic accuracy of AVQI-LT showed for both auditory-perceptual judgment procedures comparable results with two different AVQI-LT thresholds. The AVQI-LT threshold of 2.97 for the Gmean rating obtained reasonable sensitivity = 0.838 and excellent specificity = 0.937. For the VAS rating, an AVQI-LT threshold of 3.48 was determined with sensitivity = 0.840 and specificity = 0.922. CONCLUSIONS: The AVQI-LT is considered a valid and reliable tool for assessing the dysphonia severity level in Lithuanian-speaking population.

The effect of visual feedback and training in auditory-perceptual judgment of voice quality.

The aim of the present investigation was to evaluate the effect of visual feedback on rating voice quality severity level and the reliability of voice quality judgment by inexperienced listeners. For this purpose two training programs were created, each lasting 2 hours. In total 37 undergraduate speech-language therapy students participated in the study and were divided into a visual plus auditory-perceptual feedback group (V + AF), an auditory-perceptual feedback group (AF), and a control group with no feedback (NF). All listeners completed two rating sessions judging overall severity labeled as grade (G), roughness (R), and breathiness (B). The judged voice samples contained the concatenation of continuous speech and sustained phonation. No significant rater reliability changes were found in the pre- and posttest between the three groups in every GRB-parameter (all p > 0.05). There was a training effect seen in the significant improvement of rater reliability for roughness within the NF and AF groups (all p < 0.05), and for breathiness within the V + AF group (p < 0.01). The rating of the severity level of roughness changed significantly after the training in the AF and V + AF groups (p < 0.01), and the breathiness severity level changed significantly after the training in the V + AF group (p < 0.01). The training of V + AF and AF may only minimally influence the reliability in the judgment of voice quality but showed significant influence on rating the severity level of GRB parameters. Therefore, the use of both visual and auditory anchors while rating as well as longer training sessions may be required to draw a firm conclusion.

Validation of the Acoustic Voice Quality Index in the Japanese Language.

OBJECTIVES: The Acoustic Voice Quality Index (AVQI) is a multivariate construct for quantification of overall voice quality based on the analysis of continuous speech and sustained vowel. The stability and validity of the AVQI is well established in several language families. However, the Japanese language has distinct characteristics with respect to several parameters of articulatory and phonatory physiology. The aim of the study was to confirm the criterion-related concurrent validity of AVQI, as well as its responsiveness to change and diagnostic accuracy for voice assessment in the Japanese-speaking population. STUDY DESIGN: This is a retrospective study. METHODS: A total of 336 voice recordings, which included 69 pairs of voice recordings (before and after therapeutic interventions), were eligible for the study. The auditory-perceptual judgment of overall voice quality was evaluated by five experienced raters. The concurrent validity, responsiveness to change, and diagnostic accuracy of the AVQI were estimated. RESULTS: The concurrent validity and responsiveness to change based on the overall voice quality was indicated by high correlation coefficients 0.828 and 0.767, respectively. Receiver operating characteristic analysis revealed an excellent diagnostic accuracy for discrimination between dysphonic and normophonic voices (area under the curve: 0.905). The best threshold level for the AVQI of 3.15 corresponded with a sensitivity of 72.5% and specificity of 95.2%, with the positive and negative likelihood ratios of 15.1 and 0.29, respectively. CONCLUSIONS: We demonstrated the validity of the AVQI as a tool for assessment of overall voice quality and that of voice therapy outcomes in the Japanese-speaking population.

External Validation of the Acoustic Voice Quality Index Version 03.01 With Extended Representativity.

OBJECTIVES: The Acoustic Voice Quality Index (AVQI) is an objective method to quantify the severity of overall voice quality in concatenated continuous speech and sustained phonation segments. Recently, AVQI was successfully modified to be more representative and ecologically valid because the internal consistency of AVQI was balanced out through equal proportion of the 2 speech types. The present investigation aims to explore its external validation in a large data set. METHODS: An expert panel of 12 speech-language therapists rated the voice quality of 1058 concatenated voice samples varying from normophonia to severe dysphonia. The Spearman rank-order correlation coefficients (r) were used to measure concurrent validity. The AVQI's diagnostic accuracy was evaluated with several estimates of its receiver operating characteristics (ROC). RESULTS: Finally, 8 of the 12 experts were chosen because of reliability criteria. A strong correlation was identified between AVQI and auditoryperceptual rating (r = 0.815, P = .000). It indicated that 66.4% of the auditory-perceptual rating's variation was explained by AVQI. Additionally, the ROC results showed again the best diagnostic outcome at a threshold of AVQI = 2.43. CONCLUSIONS: This study highlights external validation and diagnostic precision of the AVQI version 03.01 as a robust and ecologically valid measurement to objectify voice quality.

Is the speaking fundamental frequency in females related to body height?

The aim of the study was to determine the impact of body height on speaking fundamental frequency (SF0) while controlling for as many as possible influencing factors such as habits, biophysical conditions, medication, diseases, and others. Fifty-eight females were analyzed during spontaneous speech (i.e. explaining driving directions or a cooking recipe) of at least 60 seconds at comfortable pitch and loudness. The subjects showed a moderate negative and significant correlation between body height and SF0 (r = -0.40, P = 0.002). With r(2) = 0.16, however, a reasonable portion (16%) of the variance in SF0 is explained by the variance in body height. In comparison with other factors for which a correlation with SF0 was mentioned in literature (hypothyrodism, hemodialysis, auditory-maleness after female-to-male transsexualism, body weight, body mass index, and body fat), body height accounted for most of the proportion of SF0 in females. It is therefore possible to validate body height as a factor to account for in clinical F0 measurement.

Assessment of voice quality: Current state-of-the-art.

Voice quality is not clearly defined but it can be concluded that it is a multidimensional perceived construct. Therefore, there are broadly two approaches to measure voice quality: (1) subjective measurements to score a client's voice that reflects his or her judgment of the voice and (2) objective measurements by applying specific algorithm to quantify certain aspects of a correlate of vocal production. This paper proposes a collection and discusses a number of critical issues of the current state-of-the-art in voice quality assessments of auditory-perceptual judgment, objective-acoustic analysis and aerodynamic measurements in clinical practice and research that maybe helpful for clinicians and researchers.

Do body mass index and fat volume influence vocal quality, phonatory range, and aerodynamics in females?

PURPOSE: To analyze the impact of body weight and body fat volume on selected parameters of vocal quality, phonatory range, and aerodynamics in females. METHODS: Based on measurements of body mass index in combination with body fat volume, 29 normophonic female subjects were classified as normal weight, underweight, and obese. Voice quality was investigated via auditory-perceptual ratings of breathiness, roughness, and overall dysphonia severity, via various acoustic measures and a multiparametric index. Phonatory range performance was examined using selected measures of the voice range profile and speech range profile. Measures of vocally relevant aerodynamics included vital capacity (i.e., VC), expected VC, phonation quotient, and maximum phonation time (i.e., MPT). RESULTS: Significant differences between the three weight groups were found across several measures of intensity, VC, MPT, and shimmer. As compared to the other groups, significantly higher values of maximum and minimum intensity levels, as well as sound pressure level during habitual running speech were observed for the obese group (all p-values<0.05); whereas, the underweight group had significantly lower values for VC and ratio of expected to measured VC (p-values<0.01). Furthermore, underweight subjects differed significantly as compared to normal weight subjects with lower MPT (p=0.025) and higher lowest-F0 (p=0.035). Finally the obese group showed significantly lower shimmer values than the normal weight subjects (p<0.05). CONCLUSION: Body weight and body fat volume appear to influence select objective measures of voice quality, vocal aerodynamics, and phonatory range performance.

O índice de massa corporal e o volume de gordura influenciam a qualidade vocal, extensão fonatória e aerodinâmica em mulheres? / Do body mass index and fat volume influence vocal quality, phonatory range, and aerodynamics in females?

OBJETIVO: Analisar o impacto do peso corporal e do volume de gordura corporal sobre parâmetros selecionados de qualidade vocal, tessitura fonatória e aerodinâmica em indivíduos do sexo feminino. MÉTODOS: Com base em medidas de índice de massa corporal e volume de gordura corporal, 29 indivíduos do sexo feminino, de aparelhos fônicos normais, foram distribuídos em grupos de peso normal, abaixo da média e obesos. A qualidade vocal foi investigada por meio de classificações auditório-perceptivas de soprosidade, rugosidade e severidade de disfonia por meio de várias medidas acústicas e índice multiparamétrico. O desempenho da tessitura fonatória foi examinado por meio do uso de medidas selecionadas do perfil de extensão vocal e perfil de extensão discursiva. As medidas de aerodinâmica vocalmente relevantes incluíram capacidade vital (CV), CV esperada, coeficiente fonatório e tempo de fonação máximo (TFM). RESULTADOS: Diferenças significativas entre os três grupos foram encontradas em relação a várias medidas de intensidade, CV, TFM e shimmer. Em comparação com os outros grupos, valores significativamente maiores de níveis de intensidade máxima e mínima e nível de pressão sonora durante discurso habitual foram observados no grupo obeso (todos os valores de p<0,05); já o grupo abaixo do peso apresentou valores significativamente menores para CV e para a proporção de CV esperada em relação à CV medida (valores de p<0,01). Além disso, indivíduos abaixo do peso diferiram significativamente quando comparados a indivíduos de peso normal com TFM menor (p=0,025) e F0 menor mais elevada (p=0,035). Por fim, o grupo obeso apresentou valores de shimmer significativamente menores do que os indivíduos com peso normal (p<0,05). CONCLUSÃO: O peso corporal e o volume de gordura corporal parecem influenciar certas medidas objetivas de qualidade vocal, aerodinâmica vocal e desempenho de tessitura fonatória.

PURPOSE: To analyze the impact of body weight and body fat volume on selected parameters of vocal quality, phonatory range, and aerodynamics in females. METHODS: Based on measurements of body mass index in combination with body fat volume, 29 normophonic female subjects were classified as normal weight, underweight, and obese. Voice quality was investigated via auditory-perceptual ratings of breathiness, roughness, and overall dysphonia severity, via various acoustic measures and a multiparametric index. Phonatory range performance was examined using selected measures of the voice range profile and speech range profile. Measures of vocally relevant aerodynamics included vital capacity (i.e., VC), expected VC, phonation quotient, and maximum phonation time (i.e., MPT). RESULTS: Significant differences between the three weight groups were found across several measures of intensity, VC, MPT, and shimmer. As compared to the other groups, significantly higher values of maximum and minimum intensity levels, as well as sound pressure level during habitual running speech were observed for the obese group (all p-values<0.05); whereas, the underweight group had significantly lower values for VC and ratio of expected to measured VC (p-values<0.01). Furthermore, underweight subjects differed significantly as compared to normal weight subjects with lower MPT (p=0.025) and higher lowest-F0 (p=0.035). Finally the obese group showed significantly lower shimmer values than the normal weight subjects (p<0.05). CONCLUSION: Body weight and body fat volume appear to influence select objective measures of voice quality, vocal aerodynamics, and phonatory range performance.