When designing outdoor spaces for optimal developmental acoustics, selecting the right furniture is crucial. Sound-absorbing materials like dense wood, thick cushions, and upholstered pieces can help reduce echo and noise pollution. Modular seating with built-in acoustic panels or strategically placed planters filled with dense foliage also enhances sound control. For patios and gardens, consider using heavy, textured fabrics and layered arrangements to break up sound waves. Combining functional furniture with natural elements like water features or wind chimes can further refine acoustic quality, creating a harmonious outdoor environment perfect for relaxation or social gatherings.