Backyard chill over? Being serenaded by the constant hum of passing traffic? Read on for how to reduce highway noise in your backyard.
You can’t eliminate highway noise entirely. But there are smart design, engineering, and aesthetic strategies that we can tell you about – they will help you to keep your backyard more peaceful.
Skip to:
All about highway noise
To reduce highway noise, it helps to know how sound travels and what you can realistically control:
🔊 Line-of-sight matters
Sound waves tend to travel in straight lines (especially at higher frequencies). If noise has an unobstructed visual path between source (road) and receiver (your yard), it’s more likely to reach you.
🔊 Diffraction and reflection
Sound can bend (“diffract”) around obstacles, reflect off surfaces, or scatter. That’s why even partial barriers or curved surfaces help break up direct wave paths.
🔊 Frequency dependence
Low-frequency sounds (rumble, heavy trucks) penetrate barriers more easily than high-frequency sounds (tire hiss, engine whine). So strategies often combine blocking and absorbing across frequencies.
🔊 Mass, density, and continuity
A barrier works best when it is dense (high mass per area), continuous (no gaps), and tall enough to interrupt the sound path.
🔊 Distance and absorption
The farther the barrier is from you or the noise source, the more it helps. Also, materials that absorb rather than reflect sound reduce echoes and secondary noise transmission.
How to reduce highway noise in backyard (best solutions)
No single solution will suffice in most cases. A layered or hybrid approach tends to perform best. Broadly, you can combine:
- Structural barriers (walls, fences, berms)
- Earthworks / berms / contouring
- Dense plantings / landscaping
- Sound-absorbing materials
Below, we break down each category and offer design tips:
1. Structural barriers
Solid, continuous barriers are among the most effective defenses against noise. A well-built wall or fence can block the direct sound path and reduce decibels significantly.
Key design factors:
👉 Height & alignment
To block sound, your barrier should ideally obscure the line-of-sight between your yard and the highway. The taller and closer to the source the barrier, the more effective.
👉 Mass & density
Use materials with substantial mass (e.g. masonry, concrete, thick timber, dense composite, or metal panels). Thin materials allow sound to transmit through.
👉 No gaps or seams
Even small cracks or gaps degrade performance sound will sneak through. Use overlapping boards, tongue-and-groove construction, or sealants.
👉 Absorptive surfaces
The side facing the highway should ideally be somewhat absorptive (e.g. textured, with absorptive facing) rather than purely reflective, to reduce rebound reflections.
👉 Double walls / cavity filled
If possible, a double-wall with an internal cavity filled with absorptive material improves performance.
Studies in sound barrier design suggest that a sound wall offers about 2 dBA better performance at the same height than an equivalent earth berm (because the berm must be broader, and earth is less dense).
If your local regulations restrict wall height, you might use acoustic fence panels or composite sound‐proofing panels that integrate absorptive layers. Some outdoor-rated acoustic screens or barriers (used in theater or industrial applications) can also be adapted for backyard use.
2. Earthworks / berms / contouring
An earth berm is a raised mound of soil between your yard and the road. Although less efficient per height than a rigid wall, berms can help absorb and deflect noise when space allows.
Design tips:
👉 Berms should be as close to the road/noise source as possible.
👉 Use a gentle slope (e.g. 3:1) so the mound is stable.
👉 Top the berm with soil and plantings to hide it and increase absorption (grass, shrubs, groundcover).
👉 Combine with a barrier on top to add extra height without making the berm excessively wide.
👉 Recognize that berms require land space; narrow lots may not allow effective berm width.
Because berms require wide footprints, in tight yards walls or fences may be more practical. But in suburban or rural lots with generous depth, berms can become a natural, attractive solution.
3. Dense plantings / landscaping
Plants and vegetation are less effective as a sole noise barrier, but when used as supplementary layers (especially in front of solid barriers), they help with absorption, diffusion, and psychological masking.
Best practices:
👉 Use evergreen trees and dense shrubs with year-round foliage. Their leaves, branches, and trunks help absorb and scatter sound.
👉 Plant in staggered / multi-row fashion (e.g. one row close to the road, one intermediate, one near your yard).
👉 Use varied heights (groundcover, medium shrubs, tall trees) to create a layered texture that disrupts airflow and sound paths.
👉 Keep foliage dense near the ground (no bare trunks), so sound cannot pass underneath.
👉 Native species adapted to your climate are better for maintenance and survival.
👉 In addition to absorption, landscaping offers a visual buffer (which can reduce perceived noise, “out of sight, out of mind”).
But note – vegetation rarely offers more than modest decibel reduction alone – studies indicate thick vegetation may yield decreases of up to 6 dB over extended widths (tens of metres).
4. Sound-absorbing materials
To reduce reflected noise and reverberation (especially in semi-enclosed areas like patios or gazebos), you can incorporate acoustic panels, baffles, or absorptive surfaces.
Ideas include:
👉 Cladding walls or fences with mass-loaded vinyl, acoustic mats, or perforated timber panels backed with acoustic insulation.
👉 Hanging acoustic baffles or panels from pergolas or overhead structures (specially rated for outdoor use).
👉 Using outdoor rugs, dense cushions, and soft textiles in seating zones, which absorb noise rather than reflect it.
👉 Adding lattice or trellis screens covered with climbing plants to break up sound paths.
👉 For areas adjacent to walls, attach absorptive boards (such as mineral wool or fibrous acoustic boards) behind decorative facades.
👉 Also consider sonic crystal barriers, an advanced acoustic technology research area – these periodic structures (e.g. arrays of cylinders or scatterers) create band-gap effects that can attenuate specific frequency ranges of traffic noise.
However, for a backyard residential setting the more conventional barrier + vegetation + absorption approach tends to be simpler and more cost-effective.
5. Noise masking
Sometimes the best approach is not full suppression, but masking unwanted noise with more pleasant sounds. This doesn’t reduce the highway noise itself, but makes it less perceptible.
Practical masking tactics:
👉 Water features (fountains, waterfalls, bubblers): the sound of running water can provide consistent ambient noise that “drowns out” road hum. Place the feature between your yard and the noise source.
👉 Wind chimes or rustling plants: the soft swish of leaves or chimes can help distract the ear, particularly on breezy days.
👉 Outdoor speakers / sound systems: use ambient nature audio (birdsong, wind, streams) or white-noise tracks; but be cautious about disturbing neighbors.
Masking is particularly useful for smoothing out noise fluctuations (vehicles passing, sirens), but it works best in combination with barriers and absorption.
6. Site layout / repositioning
Your own yard layout choices can help maximize quiet zones.
👉 Locate seating areas and outdoor rooms as far as possible from the highway side.
👉 Sunken seating areas: depress the floor of a patio below grade, so surrounding soil and walls act as natural buffers.
👉 Use pathways and planting lines to deflect or channel sound away from focal points.
👉 Avoid placing hard, flat, reflective surfaces (e.g. bare concrete walls) opposite the road that bounce sound inward. Use textured surfaces or slanted walls.
👉 If your property slopes, take advantage of that to interpose earth between you and the road.
Frequently asked questions
How many decibels can typical backyard sound barriers realistically reduce?
The extent of noise reduction depends on height, distance, materials, and frequency content. A well-built solid barrier of adequate height can often reduce 5 to 10 dB or more (perceived as a halving to quartering of loudness). In favorable conditions, combined barrier + berm + absorption systems can reach reductions of 10–15 dB or more for mid and high frequencies.
Why do I hear low-frequency rumble even after installing a fence?
Low-frequency sounds (e.g. heavy trucks, bass) have long wavelengths and can diffract over or around partial barriers. They penetrate materials more easily and bypass gaps. That’s why even a stout barrier may reduce higher frequencies more than deep hum. Solutions include adding mass (dense materials), sealing all gaps, and possibly subsurface vibration damping.
Do plants alone really help with noise?
Plants primarily act as secondary absorbers / diffusers more than strong blockers. Dense, wide, multi-meter plantings can contribute 2–5 dB of reduction — but only if foliage is thick, near-ground, and covers barriers. Their biggest value is visual screening, psychological effect, and improving overall acoustic texture.
If wall height is limited by regulation, what can I do?
If maximum permitted wall height is low, consider; combining with a berm underneath, so the effective barrier line is higher; using double-wall / stepped design to create a staggered barrier; placing barriers closer to the source (so effective height vs road is greater); or using absorptive panels on top of permitted walls to gain acoustic benefit without raising physical height.
Will sound bounce off my barrier and affect neighbors?
Yes, reflective barriers may direct noise to adjacent properties. To mitigate this, use absorptive surface materials on the road-facing side, use angled or curved top edges to scatter reflections, and add vegetation in front of the wall to catch reflections.
Can I use speakers or sound systems safely to mask noise?
Yes, masking is effective, but you must use outdoor-rated equipment, weatherproof and set at appropriate volume. You should also choose ambient or natural sounds (water, wind, forest) that don’t compete; put direct speakers inward (toward your yard) not outward; be considerate of neighbors coordinate usage times and volume, and consider smart volume control so masking adapts to actual noise levels.
How do I position a water feature for masking?
Place it between your seating area and the highway so the water sound is closer to you than the noise source. A few small cascading or bubbling fountains spaced along a barrier often provide more even masking than one large feature. Adjust the height and flow so the water’s sound is audible but not overpowering.
Is a sunken patio really effective
Yes. By dropping the seating plane below ground level, surrounding soil, retaining walls, and plantings block or absorb sound before it reaches you. A sunken layout gives you “inside the mound” protection against airborne noise.
When should I call a professional?
If you have especially high noise intrusion (major highway, heavy trucks), limited space, or regulatory constraints, a professional acoustic consultant or landscape architect can model noise paths and recommend custom barrier geometry, materials, and layering. They can quantify expected decibel reduction and help with permitting.
How much does it cost to reduce highway noise in a backyard?
The overall cost of reducing highway noise in your backyard depends heavily on the type of solution you choose, the size of your property, local labor rates, and how much of the work you plan to do yourself. A basic wooden or vinyl privacy fence typically costs between $25 and $60 per linear foot.
If you opt for acoustic or soundproof fencing panels, expect to spend $70 to $150 per linear foot. These are specifically engineered for noise control, using absorptive cores or mass-loaded vinyl layers, and can reduce sound by 8 to 12 decibels under the right conditions. Masonry or concrete sound walls offer some of the best performance and longevity but come at a premium, generally running between $90 and $200 per linear foot, not including foundation work or permits.
In total, most moderate backyard noise-control projects fall within $3,000 to $15,000, enough to achieve noticeable reductions and improved comfort. For larger or high-end projects – such as engineered sound walls combined with extensive landscaping, berms, and decorative water features – budgets can reach $20,000 to $40,000 or more.
