Method: The patient population consisted of 93 patients undergoing video fluoroscopic swallowing study (VFSS) to evaluate the risk of aspiration. The voice analyses were performed before and after VFSS using a portable recorder and voice analysis. The parameters included Average Fundamental Frequency (Fo), Relative Average Perturbation (RAP), Shimmer Percent, Noise to Harmonic Ratio (NHR), and Voice Turbulence Index.

Results
: The patients were divided into two groups according to VFSS findings, non-aspiration group (including patients without vocal cord contact) and aspiration group (including patients with vocal cord contact). In comparing the differences of acoustic parameters before and after VFSS, all parameters except Fo were significantly different (p＜0.05). When the cut-off point was set to 0.3, the RAP was the most significant parameter given that the sensitivity was 0.911 and the specificity was 0.979. Combining RAP and NHR, the sensitivity was 1.000 and the specificity was 0.771.

Conclusion: Voice analysis is a very convenient and effective diagnostic tool in clinically evaluating the risk of aspiration. (J Korean Acad Rehab Med 2003; 27: 984-989)