The purpose of this work is to analyze the impact of airborne ultrasound on the drying efficiency of biological materials (Lobo apples). Experimental kinetics curves for drying apples were obtained from tests done in a hybrid dryer equipped with a new plate-transducer in an ultrasonic power generator. These curves were used to validate the numerical kinetic curves determined on the basis of a drying model that was developed by the authors. The intensification of heat and mass transfer by drying due to ultrasound provoked "heating effect" and "vibration effect" are analyzed. The obtained results allow to state that ultrasounds make the drying processes more effective and enhance the drying efficiency of biological products without significantly raising their temperature. (C) 2015 Elsevier Ltd. All rights reserved.