When it comes to reducing the noise you hear in your yard, the more you know about how sound travels, the better. Sound waves travel on air and, like water, air will take the path of least resistance. This means any gaps in the fence allows the air and the sound waves it's carrying to enter your yard. Close the gaps and you'll block the air and the sound waves.
Privacy fences are generally made of either wood or vinyl and range in height from 4 to 8 feet. For a privacy fence to reduce noise, they need to be solid in construction. Each board of the fence must be snugly butted up against the next with no gaps between them. The fence also needs to extend fully to the ground. Any gaps at the bottom of the fence or between the individual pieces of the fence allows the sound to flow through, reducing or eliminating the noise reduction properties.
Stone fences contain pieces of stone of various shapes and sizes. Depending on the construction method, the stones may or may not be set in mortar. Stone fences are typically shorter than privacy fences because of the cost and labor involved in construction, and because the higher the stones are stacked, the less stable the fence is. Because stone fences are thicker than wood privacy fences, their noise reducing qualities are greater than those of wood fences.
Brick fences are walls constructed of brick. The brick is set in mortar, which allows brick fences to be tall without compromising stability. The bricks are often laid in decorative patterns so the brick fence is not only functional but attractive as well. Brick fences are also thicker than wood privacy fences, so they offer more noise deadening properties than wood fences. If the brick fence is taller than a stone fence, it'll offer more noise reduction. If the two are the same height, the noise reduction difference between them is generally indistinguishable.
Living fences are made of a organic material such as shrubbery or trees. The height and density of living fences determine the amount of noise reduction they'll provide. Newly planted hedges and shrubs allow more noise to flow between them, but as they mature, they'll grow together and the noise will be blocked. Create noise reduction while allowing room for growth by layering your living fence materials. Start by planting trees at the edge of your property, then plant shrubbery in front of the trees. Stagger the shrubs so they're in front of and between the trees.