This study attempts to determine the fundamental frequency level of male and female voices that Koreans perceive as normal. Seventy-three college students majoring in Speech Pathology participated in the study on a voluntary basis. The subjects listened to a male voice with fundamental frequency of 60 Hz, 80 Hz, 100 Hz, 120 Hz, 140 Hz, 160 Hz, 180 Hz, and 200 Hz, and a female voice with fundamental frequency of 140 Hz, 160 Hz, 180 Hz, 200 Hz, 220 Hz, 240 Hz, 260 Hz, and 280 Hz. The PSOLA (Pitch Synchronous Overlap). method and harmonic modeling method of speech signal were used to change pitch in the 20 Hz interval. The voices were presented in a random order to prevent listener bias. The results were as follows; Firstly, $46.6\%$ judged male voice with 120 Hz as normal, and $19.2\%$ judged 140 Hz as normal, and another $19.2\%$ judged 160 Hz as normal. Secondly, $50.7\%$ perceived female voice with 220 Hz as normal, and $32.9\%;and;30.1\%$ responded to 200 Hz and 240 Hz, respectively. The problems and recommendations for a future investigation are discussed.