In a Hawaii coral experiment published in October 2026, scientists put an underwater speaker beside 3D-printed structures and bacteria-coated concrete blocks; coral larvae settled on coated blocks but not bare controls

• Coral larvae settled most near the speaker, with bacteria-coated structures showing stronger results than artificial surfaces alone.
• A reef may be built from concrete and carefully engineered structures, but for young marine life, it appears that the right soundtrack could matter too.
• The results offer an intriguing new direction for reb