For the inner geek in all singers and other professional voice users, you can now download onto your iPhone an advanced voice analysis program that provides objective measures of vocal quality similar to what is obtained in a professional voice laboratory. Called OperaVox , preliminary studies have shown good reliability compared to KayPentax Multidimensional Voice Program (f0, shimmer, jitter). Noise to harmonic ratio showed less reliability. Retest reliability was also fairly consistent i…