Species of the genus Endecous are found in tropical and sub-tropical forests of the neotropical region. Most of the studies of the species in this genus are limited to short descriptions based on external morphological characters. At present, eleven species of Endecous have been described, five of them collected in Brazilian territory. Four of them are considered here: E. itatibensis, E. cavernicolus, E. abbreviatus, E. betariensis and also a new species from a cave close to Goianésia town, Goiás State. We describe here the acoustic repertoire in the genus Endecous and we apply these results to solve related taxonomic problems. The species here analysed emit six different acoustic structures with distinct biological functions, related to mating (song for female calling, female recognition, courtship, copulation) and to hierarchical and aggressive behaviour. The main differences between species are in the number of notes in the calling song chirps, which is the most species-specific character. The results we obtained through this acoustic analysis suggest that itatibensis and abbreviatus are the same species.