In the present invention, a biological sound is accurately extracted from noisy acoustic data. A machine learning apparatus (1) is for learning a predictive algorithm (D2) for predicting whether a biological sound is included in acoustic data. The machine learning apparatus (1) is provided with: an acoustic data acquisition unit (121) that acquires the acoustic data obtained from a subject by a sound collection device (4); a biological sound determination unit (123) that determines whether or not the biological sound is included in the acoustic data, in accordance with a user's operation; a feature amount extraction unit (124) that extracts a feature amount in the acoustic data; and a learning unit (13) that learns the predictive algorithm on the basis of the feature amount and a result of determination by the biological sound determination unit (123). The feature amount includes at least any one of PNCC, MFCC, ΔPNCC, ΔΔPNCC, ΔMFCC, ΔΔMFCC, BSF, a feature related to a formant, a feature related to a pitch, an LPC coefficient, spectrum flatness, logarithmic energy, a duration time period of a sound segment, ZCR, an index based on entropy, and the statistics thereof.