Based on linear one‐dimensional acoustics, a geometrically perfect elastic waveguide would respond to an oscillatory internal pressure only in the presence of path deflectors (elbows and branches). In practice, a significant elasto‐acoustic interaction results even in straight conduits as a result of manufacturing tolerances. A theoretical model of the linear acoustic loading in straight pipes is developed that considers the acoustic wave distortion due to perimeter, axial, and wall thickness nonuniformities.