What is the term for the transmission of sound along a curved surface?

The term for the transmission of sound along a curved surface is known as "creep." This phenomenon occurs when sound waves travel along the surface of a medium, often bending and following the contour or curvature of that surface. Acoustic creep is particularly relevant in environments such as concert halls or auditoriums, where the shape and materials of the surfaces can significantly influence sound propagation.

In contrast, "echo" refers to the reflection of sound that arrives at the listener after bouncing off a surface, while "rotunda" is an architectural term for a rounded building or space, which does not directly relate to sound transmission. "Curve" is a general term that describes the shape but does not specifically define the process of sound transmission along that shape. Thus, creep is accurately aligned with the description provided in the question.