A peak of acoustic emission (AE) is observed experimentally at the superconducting transition temperature in samples of the superconducting ceramicsTl2Ba2CuO6+x.AE signals have been recorded by a piezoelectric transducer with the resonant frequency 1 MHz in the temperature range 80–300 K. Relaxation anomalies are attributed to a change in the charge state of linear defects and variations of the parameters of the cuprate layer in the samples. ©1998 American Institute of Physics.