This is one of the more simpler achievements placed in the game and can be unlocked within a few seconds of beginning the game.
Once you have loaded the game '
Ecco The Dolphin' head to the right to leave the start area and head towards another Dolphin (There are 3 right outside when you exit) press
next to one to use your sonar to talk to them and the achievement should be yours.
Here's a video demonstration