This study investigated the accuracy of mothers' reports of their babies' c
rying. The crying of babies, 5-16 weeks old, was recorded by means of a wir
e-less, miniature microphone contained within a terry cloth belt worn by th
e baby. Crying was transmitted to a voice-activated recorder with a range o
f 500 feet. Thirteen 24-hour recordings were obtained from seven infants wh
ile, at the same time, the mothers kept a Cry Log of their baby's crying. T
he number of minutes of crying and the number of bouts of crying obtained f
rom the two procedures were highly correlated, although the amount of cryin
g reported by the mothers was less than that obtained from the recorder. Th
e mothers reported fewer bouts of crying. The results suggest that maternal
cry reports are valuable for obtaining relative amounts of crying of infan
ts within a group, as well as information on mothers' perceptions of their
infants' crying, whereas audio recordings offer a more precise method for o
btaining the amount and temporal patterning of infant crying.