Most current noise barriers are cement-based, but geopolymers present an intriguing alternative for various applications due to their potentially low CO₂ footprint. This reduction is achievable because geopolymers can be synthesized using lower-energy primary raw materials and incorporate secondary raw materials, reducing both environmental impact and reliance on high-energy inputs.Geopolymer-based porous wall elements, designed for noise reduction, offer further advantages beyond environmental benefits. Their intrinsic porosity enables acoustic absorption, making them highly suitable for effective noise barriers. The material structure can be tailored to deliver durable performance in diverse climates, including resilience to freeze-thaw cycles, stability and overall structural integrity.These noise barriers can be produced as gabions or as panels. To tune the absorption spectra the processing is adapted in a way to achieve a bimodal particle size distribution or a double porous structure. Some parameters to influence the outcome material are introducing seeds with different sizes, reaction kinetics of the geopolymers by mixture design, and adapting the agitation speed in the mixer. The pore and particle size distributions are meticulously analyzed using micro-CT imaging, complementing acoustic absorption measurements, to ensure the material meets stringent performance criteria.