Psychoacoustic tuning curves were obtained in nine normal subjects, ten mild conductive hearing loss subjects, five mild perceptive hearing loss subjects, and five moderate perceptive hearing loss subjects. Normal psychoacoustic tuning curves are composed of down sloping curve and upsloping curve, with its acute angled tip at the probe tone frequency and tail formation in lower frequencies. With conductive hearing loss, there was no significant change of the shape of the curve, expect the elevation of maksing threshold. With perceptive hearing loss, there were broadening of the curve and loss of its acute angled tip, suggesting loss of frequency selectivity in these cases, and the broadening effect was more remarkable in the more severe hearing loss.