Therapeutic ultrasound is one of the most used electrotherapy resources in the rehabilitation process. Due to the high frequencies of ultrasound waves, when in contact with the human body, this mechanical wave will be propagated through the tissues and promote heating and other non-thermal effects to potentiate the rehabilitation process. The present study aims to analyze the attenuation of the ultrasound wave as it passes through each layer by using Phantoms to observe the real relationships established between them. Our findings indicate that biological tissues exhibit diverse behaviors, despite their characteristics and varieties, they display exponential responses to acoustic energy and heating. We emphasize to healthcare professionals the significance of accurately calculating appropriate energy levels. Similarly, for professionals engaged in the development of medical equipment, the importance of inserting these variables in the equipment composition.