This study presents the preparation and property characterization of biomass aerogels as sound absorption materials. Biomasses were chosen to prepare aerogels through the freeze-drying method. Results indicated that four components may have different effects on the aerogel pore structure, and the aerogel formula was thus optimized to reach the best sound absorption. Within the experimental range, biomass aerogel with the optimized formula had an average sound efficiency 0.352, density 0.047 g/cm³ and porosity 94.46 ± 0.04%. It shows better sound absorption performance than traditional sound absorption cotton. These results demonstrate the high sound absorption potential of biomass aerogels for building applications.