The only way to interact and study sperm whales is by freediving with them since they get disturbed by the noise of scuba- and other technical gear.
It’s only by freediving with them that interaction can occur, where they usually end up inviting you to the pod after a first sonar scan.
Sperm whales sends out sonar pulses to scan their surroundings, including you when you’re close.
This calf is sending out sonars to scan the freediver’s body and interior - the kidneys, lungs, rib cage to get a full 3D picture of what she is.
This echolocation sounds like a clicking sound, almost like morse code.
Sperm whales can click at about 236 decibels, which is the loudest animal on the planet.