A problem of nonstationary hydroelectroelasticity is solved to determine the pressure in the ambient medium when a spherical thin-walled piezoelectric transducer with a shield either inside or outside is excited with an electric pulse Keywords: nonstationary hydroelectroelasticity, electric and acoustic pulses, conversion, piezoceramic spherical shell, inside and outside shields Introduction. Nowadays, the piezoelectric effect is widely used in the industry, which explains the considerable interest in piezoceramic materials and devices made from them.The widespread use of piezoceramics is due to their capability of converting mechanical energy to electric energy, and vice versa. Today, piezoceramic transducers are employed in various areas of modern technology, medicine, biology, and agriculture. They are most popular in sonar systems used in navigation safety, ocean research, marine geology, fishery, monitoring and analysis of the acoustic fields of ships and parameters of sonar equipment.Of the widest use are plate, rod, cylindrical, and spherical piezoelectric transducers. Piezoelectric plates mainly operate to receive acoustic vibrations and convert them into electric signals. Rod, cylindrical, and spherical transducers either generate or receive acoustic vibrations. Applied hydroacoustics is currently interested in the use of electric pulses with a complex law of voltage variation for the nonstationary excitation of piezoelectric transducers. The overwhelming majority of the available publications on the nonstationary hydroelectroelasticity of thin-walled piezoceramic shells studies the nonstationary behavior of cylindrical shells [1][2][3][4][5]. Those few publications that address transient modes in spherical piezoceramic shells [11], spherical piezoceramic shells with inside impedance shield [12], and two concentric spherical piezoceramic shells [1, 6] do not provide methods and a theory for the development of modern sonar systems.The present paper is concerned with the transients induced by a variable voltage in a thin-walled piezoceramic spherical shell (piezoelectric transducer) with a perfectly rigid spherical body inside (internal rigid shield) or an elastic shell inside or outside. This shielded transducer is placed in a fluid. Formulating problems of this class, developing methods to solve them, and establishing transient patterns are of current importance for modern acoustics because of the demands of advanced engineering. Note that the nonstationary electroelasticity and vibrations of cylindrical shells with a fluid were studied in [14][15][16][17].