Underwater sounds lead search for missing Titan submersible despite challenges

Search teams have detected noises from the area where the Titanic submersible disappeared.
The ocean environment produces many sounds, complicating efforts to locate the source of any one noise.
The Coast Guard heard intermittent banging sounds, but it is unclear if they came from the submersible.
Sound travels farther underwater than on land, so listening is the best way to find the submersible.
The way sound bends and echoes underwater poses difficulties in pinpointing the origin of any sounds that are detected.