To verify the influence of the age of implantation in the development of closed-set auditory recognition and auditory comprehension abilities in children using unilateral cochlear implants (CI), comparing distinct groups and determining clinical markers.Participants were 180 children operated and activated until 36 months of age and who used a CI for at least 60 months. Abilities of auditory recognition in closed-set and auditory comprehension were analyzed through the GASP Tests 5 and 6. The influence of age of implantation was investigated with three groups of children: implanted before 18 months (G1), between 19 and 24 months (G2) and between 25 and 36 months of age (G3).There was no statistically significant difference when comparing the three groups. Children progressively developed auditory abilities, presenting auditory recognition ability together at approximately 41±4 months of CI use and auditory comprehension at 53±4 months.There was no correlation between hearing performance and age of implantation for children implanted before 36 months of age. For the abilities of auditory recognition and comprehension, the clinical marker was 41±4 and 53±4 months of auditory age, respectively. Therefore, it is expected that, around 60 months of CI use, children implanted during the sensitive period can understand speech without the aid of orofacial reading, reaching the most complex hearing abilities.