The vocal ontogeny of a species is enlightening with regards to their physical development and capacity for social learning. North Atlantic right whales (Eubalaena glacialis) are an endangered species with a wide range of vocalizations including complex tonal and pulsive calls, stereotyped tonal upcalls and broadband gunshot sounds. We investigated the development of vocalization use from birth to adulthood, tracking both physical and social maturation in acoustic communication. Right whale calf calls were characterized from  <1 month (nursing calf) to >9 years (adult) in age to explore the development of their vocalization with growth. Calls were recorded across a range of right whale research projects conducted between 2005 and 2014 in the Bay of Fundy, Canada; and coastal Massachusetts, Florida and Georgia, United States. Whales were tagged using a non-invasive archival digital acoustic recording tag (DTAG). Individuals were photographed for identification. Age was calculated from documented observations of mothers with their calves as part of the North Atlantic Right Whale Consortium database. Calls were sorted by age and both male and females were included in the analysis. In addition, discriminant function analysis was used to determine whether a calf could be aged by its call. The significance of the vocal development patterns observed in this species will be discussed.