ᐅ Fence as noise protection from the neighbor. What materials or designs are most effective at blocking sound?

Hello,

We want to build a fence a few meters away on the neighbor’s property line, mainly to reduce the noise disturbance for our neighbor.

Our neighbor (75 years old) is bothered by the fact that our children (2 and 6 years old) play a lot in the garden, especially now during the holidays and the nearly unbearable heat during the day. They sometimes play outside until just before 8 p.m., as our property is pleasantly shaded from 6 p.m. onwards.

Since the sandbox, pool, and mud kitchen are located close to the property boundary near the neighbor, their terrace is quite close to the activity. Our older child has a hearing impairment and a very sensitive ear, which causes him to speak and shout loudly while playing (which also annoys us), and the younger one naturally raises their volume as well.

So, I had the idea to build a wall on our side in this area to reduce the noise he hears from us. The initial idea was a basement block or formwork block wall, although visually it’s not very appealing and looks more like a silo wall.

Have any of you done something like this before and possibly have suggestions on what absorbs sound best? Whether a solid wooden fence, a dry-stone wall, or a gabion wall… just the required height would be a lot of work with foundations, etc.