Recognition of two psychological conditions of a single cow by her voice

A study was made to recognize the changes in the vocalization of a cow under two types of psychologically stressed conditions—being hungry before feeding, and being separated from her calf for weaning. The change of the spectral structure of the voice signal was used to recognize these two conditions. The lowest six resonant frequencies of the voice signals recorded for the hunger condition were higher than those for the separation, and almost all vocalizations for these two conditions could be recognized by the linear discriminant analysis of the resonant frequencies.