Internal Validation of the Acoustic Voice Quality Index version 03.01 und Acoustic Breathiness Index

Abstract

Acoustics might have the potential to objectify voice quality (eg, hoarseness and breathiness). The Acoustic Voice Quality Index (AVQI) and the Acoustic Breathiness Index (ABI) revealed sufficient valid and reliable results in the evaluation of voice quality. The aim of the present study is to validate the recent version of AVQI 03.01 and ABI in their internal validation. The responsiveness of change is evaluated on the hoarseness and breathiness severity after voice therapy. In total, 84 voice samples of continuous speech and sustained vowel [a:] before and after a voice therapy were used. All 42 subjects presented organic and nonorganic voice disorders and various degrees of dysphonia severity before and after behavioral voice therapy. The voice samples were judged by three voice experts using the RBH-scale, which is based on the GRBAS-scale. The intra-rater reliability was high for hoarseness (mean kappa = 0.76) and breathiness (mean kappa = 0.69).The inter-rater reliability was lower for both voice quality characteristics and ranged between kappa = 0.27 to 0.29. A strong correlation was identified between the perceived rating of hoarseness and breathiness and AVQI and ABI before and after voice therapy (r = 0.715, p < 0.01, and r = 0.712, p < 0.01, respectively). Additionally, no significant differences were revealed. The present results showed that AVQI version 03.01 und ABI had a high internal validity to assess voice changes after voice therapy. AVQI and ABI are two valid and robust voice measures to objectify hoarseness and breathiness.