Which technique is NOT commonly used in room acoustics design?

In the context of room acoustics design, echo cancellation is not a commonly used technique. Room acoustics focus primarily on how sound behaves within a space and involves managing sound reflections, absorption, and diffusion to optimize audio quality.

Acoustic paneling is widely implemented to absorb sound and reduce excessive reverberation, which helps create a clearer listening environment. Bass traps are specifically designed to address low-frequency issues by absorbing bass sounds that tend to accumulate in corners, improving bass response in the room. Diffusers scatter sound waves to prevent focused reflections, contributing to a more balanced acoustic environment.

Echo cancellation, on the other hand, is primarily a technology used in telecommunications and audio processing contexts to mitigate echoes during audio transmission, rather than a design technique for shaping the acoustic properties of a room. Hence, this makes it the least applicable technique in the context of room acoustics design.