Which of the following increases a noise barrier's effectiveness?

Creating a single, continuous barrier significantly enhances a noise barrier's effectiveness because it allows for uninterrupted attenuation of sound waves. When the barrier is continuous, it prevents sound from bypassing the structure through gaps or openings, which can occur if the barrier is not built as a complete wall. Sound waves can diffract around or through breaks in the barrier, which diminishes the overall noise reduction capability. A seamless structure absorbs and reflects the sound more efficiently, resulting in a greater overall reduction of noise levels in the areas protected by the barrier.

In contrast, building the barrier far from the noise source may not be as effective since the distance alone does not ensure adequate sound reduction, especially for lower frequencies that can travel over longer distances. Using low-mass materials can be counterproductive, as more mass generally contributes to better sound insulation. Lastly, adding decorative features may improve aesthetics but does not inherently enhance the barrier's functional capacity to attenuate noise.