A baby’s name is generally used much more often than other words. Studies show that babies are early as 4 months old prefer the sound of their individual name to that of other names. This does not mean that they understand that this is their name; rather, they are simply able to recognize the sounds that make up their name.
References:
Golinkoff, R. M. and Hirsh-Pasek, K. How babies talk: The magic and mystery of language in the first three years of life. New York: Plum.
Mandel, D. R., Jusczyk, P. W., & Pisoni, D. B. (1995). Infants’ recognition of the sound patterns of their own names. Psychological Science, 6, 314
