Comparison between OperaVOX™ and MDVP: Preliminary Results

Abstract

Objectives: Objective evaluation of voice, such as acoustic analysis, provides additional evidence in treatment monitoring. Currently, it is only possible in voice laboratories in hospitals. OperaVOX™ (On Person RApid VOice eXaminer), a portable voice analysis running on an Apple™ iPod, iPhone, and iPad, was developed to enable remote voice assessment. Our goal was to evaluate the agreement between OperaVOX™ and Multidimensional Voice Program (MDVP, KayPentax, NJ, USA). Methods: A group of 16 healthy volunteers without voice complaints were recruited from the University College London Hospital NHS Trust from December 2012 until January 2013. Supervised recordings were performed in a quiet room. A five-second recording of a sustained vowel /a/ was used to measure fundamental frequency (F0), jitter, shimmer, and noise-to-harmonic ratio (NHR). The audio files recorded using OperaVOX™ were also analyzed using the MDVP. 95% limit of agreement (LOA) between software was analyzed using the Bland Altman method. Results: The mean difference (SD) of F0, jitter, shimmer, and NHR between OperaVOX™ and MDVP measurements was -0.14 (1.28 ) Hz, -0.06 (0.32)%, -0.26 (0.67)%, and 0.12 (0.02) respectively. The 95% LOA of OperaVOX™„ to MDVP for F0 was -2.67Hz to +2.39Hz; jitter was -0.57% to +0.68%; shimmer was -1.6% to +1.09%; and NHR was +0.08 to +0.12 compared to MDVP. Conclusions: OperaVOX™ at this stage has been shown to be a promising portable voice analysis tool for measuring the F0, jitter, and shimmer of voice since the 95% LOA were within clinically acceptable levels. Agreement with PRAAT is currently being tested.