Scientists have reportedly discovered a new tool that could help with coral reef restoration efforts. A team of researchers and marine biologists set up underwater loudspeakers to play recorded sounds of healthy reefs as an experiment to lure young fish to swim in areas where the coral had degraded, Cnet reports. The six-week experiment found that by playing healthy reef sound, the total number of fish arriving in the degraded coral areas doubled and also increased the number of species by 50 per cent.