Final answer:
Sound energy that is not reflected is either absorbed, where the material takes in the sound energy often turning it into heat, or transmitted, where the sound passes through the material. In some situations, sound can be both absorbed and transmitted to different extents by a material.
Step-by-step explanation:
Sound energy that is not reflected can either be absorbed or transmitted through the medium. When sound energy is absorbed, the material captures the sound energy, and it is often converted into heat. On the other hand, when sound energy is transmitted, it travels through the material without being absorbed. It is important to understand that in some cases, sound can be both absorbed and transmitted to varying degrees by the same material.
For example, when sound encounters a thick curtain, some of the sound waves may be absorbed by the fabric, thereby reducing the noise level on the other side, while some may transmit through it. This concept is crucial when designing buildings for good acoustics or when creating materials to serve as sound insulators.