To do this, dolphins send out loud pulses of sound at very fast rates. When these sound pulses strike an object, they are reflected from it and return to us as echoes. Those echoes are to dolphin ears what light is to your eyes. To read more about echolocation, click here. Yes, dolphins do have a sense of taste, but no sense of smell.
Dolphins do have a very refined sense of touch, and the skin everywhere is sensitive to stimulation.