The effect of unilateral and bilateral destruction of the inferior colliculi on the auditory system sensitivity, sonar signals' parameters and the Doppler shift compensation in echoes was studied in horseshoe bats Rhinolophus ferrumequinum. Complete bilateral destruction of the inferior colliculi did not produce the auditory system disfunction, but it sharply decreased auditory sensitivity of this system which was manifested in a reduction of the maximum detection range and inability to detect a weakly sounding insect. The data obtained suggest that the inferior colliculi are immediately responsible for the maintenance of emitting frequency and that the role which various regions of inferior colliculus play in that process is different. To preserve the effect of the Doppler shift compensation it is necessary to keep intact not less than a half of the central nucleus at least of one inferior colliculus.