Interesting post at Smithsonian.com about new research which suggests that contrary to popularly held opinion, fathers can be just as good at recognizing their distinct baby's cry as a mother can. It all comes down to time spent parenting (not surprisingly)
The article says:
The results suggest that experience and learning may be more critical to good parenting than innate skills. Far from being inherently disadvantaged in recognizing their babies’ cries, males who spent lots of time parenting turned out to be just as good as females at the task—so in terms of this particular skill, at least, parenting is less an inherent talent than a one to be practiced and developed. This also implies that whoever is the primary caregivers for a baby—whether grandparents, aunts, uncles or people unrelated to the child—may develop the same ability to distinguish the cries of the child in their care from other children.
It goes on to say:
Fathers might have the same innate parenting skills as mothers, but only if they make the enormous time investment necessary. This study indicates that it’s usually not the case, and though its sample size was extremely limited, broader data sets show the same. According to the most recent Pew Research data on parenting, the average American mother spends 14 hours per week in child care duties, compared to just 7 hours for the average father—so while men can develop the ability to know their babies just as well as women, most fathers out there probably haven’t so far.
Again, you can find the article here on the Smithsonian blog.