Engineers carefully choose the "shape" and "material" to control sound waves.
The shape of a room, object, or device can affect how sound waves travel, reflect, and interfere with each other. Engineers use principles of acoustics to design spaces and objects that can control the propagation of sound waves, for example, to prevent echoes or to create a desired acoustic environment.
The material of a surface can also affect how sound waves behave when they interact with it. Some materials absorb sound, while others reflect it, and the choice of material can have a significant impact on the acoustics of a space. Engineers select materials based on their acoustic properties to achieve the desired sound control or quality.