Which landscaping feature can help reduce noise pollution?

Planting dense evergreen trees as a sound barrier is an effective way to reduce noise pollution. These trees create a natural barrier that can absorb, deflect, or refract sound waves, which diminishes the amount of noise that reaches residential areas or workplaces. Evergreen trees maintain their foliage year-round, providing continuous coverage and an ongoing buffer against noise throughout all seasons. Their dense branches and leaves help to create a more tranquil environment, making them excellent choices for noise mitigation in landscaping.

The other choices may not provide the same level of effective noise reduction. Low-growing shrubs can contribute to sound dampening, but they are not as effective as mature, dense evergreen trees due to their lower height and less substantial ability to block sound waves. Synthetic materials can be useful in different landscaping contexts but generally do not absorb sound and could even enhance noise reflection. High walls can block noise, but they may create an unwanted echo effect and do not provide the aesthetic benefits or environmental advantages that living plants do.