After decades of research, the origins of human speech remain little understood. One undoubted problem is that the vocal repertoires of humans’ closest living relatives, the apes, remain poorly described. Given that the evolution of language has left few fossils, many researchers interested in this question adopt a comparative approach, examining differences and consistencies between human and animal communication. However, comparisons will remain limited in the absence of a comprehensive analysis of the vocal repertoires of the other extant apes, especially of our two closest living relatives, the chimpanzee and bonobo. After years of observing and conducting field experiments with both western and eastern chimpanzees, I posit several reasons why a comprehensive analysis of the chimpanzee vocal repertoire has not yet been completed, in spite of 45 years of research, and what can be done to remedy this situation. I also tabulate cross-site consensus in call categorization, associated contexts of usage and potential call functions. I also note cross-site variation in presence and absence of vocalizations.