A hearing-ability measurement device that measures a hearing-ability of a subject, said hearing-ability measurement device comprising: a test sound generation unit configured to generate a test sound, the test sound including a probe and a masker; a test sound output unit configured to output the test sound generated by said test sound generation unit to the subject; a perception examination unit configured to examine whether or not the subject perceives the probe; and an adjustment unit configured to (i) when said perception examination unit determines that the subject perceives the probe, adjust at least one acoustic property from among acoustic properties including a spectral property of the masker, a temporal property of the masker, a sound pressure level of the masker, and a sound pressure level of the probe, so that the subject is less likely to perceive the probe, and (ii) when said perception examination unit determines that the subject does not perceive the probe, adjust the at least one acoustic property, so that the subject is more likely to perceive the probe, wherein said adjustment unit is configured to (i) when an examination result of said perception examination unit is same as a most-recent examination result, adjust the at least one acoustic property that is a most-recently adjusted acoustic property, and (ii) when the examination result of said perception examination unit is different from the most-recent examination result, adjust the at least one acoustic property from among the acoustic properties except a most-recently adjusted acoustic property, said test sound output unit is configured to output the test sound having the at least one acoustic property adjusted by said adjustment unit, and said hearing-ability measurement device measures the hearing-ability, by repeating a plurality of times the examination of said perception examination unit, the adjustment of the at least one acoustic property of said adjustment unit, and the output of the test sound of said test sound output unit. a test sound generation unit configured to generate a test sound, the test sound including a probe and a masker; a test sound output unit configured to output the test sound generated by said test sound generation unit to the subject; a perception examination unit configured to examine whether or not the subject perceives the probe; and an adjustment unit configured to (i) when said perception examination unit determines that the subject perceives the probe, adjust at least one acoustic property from among acoustic properties including a spectral property of the masker, a temporal property of the masker, a sound pressure level of the masker, and a sound pressure level of the probe, so that the subject is less likely to perceive the probe, and (ii) when said perception examination unit determines that the subject does not perceive the probe, adjust the at least one acoustic property, so that the subject is more likely to perceive the probe, (i) when said perception examination unit determines that the subject perceives the probe, adjust at least one acoustic property from among acoustic properties including a spectral property of the masker, a temporal property of the masker, a sound pressure level of the masker, and a sound pressure level of the probe, so that the subject is less likely to perceive the probe, and (ii) when said perception examination unit determines that the subject does not perceive the probe, adjust the at least one acoustic property, so that the subject is more likely to perceive the probe, wherein said adjustment unit is configured to (i) when an examination result of said perception examination unit is same as a most-recent examination result, adjust the at least one acoustic property that is a most-recently adjusted acoustic property, and (ii) when the examination result of said perception examination unit is different from the most-recent examination result, adjust the at least one acoustic property from among the acoustic properties except a most-recently adjusted acoustic property, (i) when an examination result of said perception examination unit is same as a most-recent examination result, adjust the at least one acoustic property that is a most-recently adjusted acoustic property, and (ii) when the examination result of said perception examination unit is different from the most-recent examination result, adjust the at least one acoustic property from among the acoustic properties except a most-recently adjusted acoustic property, said test sound output unit is configured to output the test sound having the at least one acoustic property adjusted by said adjustment unit, and said hearing-ability measurement device measures the hearing-ability, by repeating a plurality of times the examination of said perception examination unit, the adjustment of the at least one acoustic property of said adjustment unit, and the output of the test sound of said test sound output unit.