The LAB, in collaboration with Acquopolis de la Pineda (Parques Reunidos, S.A.) and the Barcelona Zoo, are measuring audiograms of dolphins with an autonomous portable system with the purpose of calibrating and diagnosing possible auditory losses due to the captive conditions. The results of this analysis can be used in stranding situations and complement the information at the moment when a decision has to be taken whether an animal is returned to the sea of rehabilitated in a recovery centre.