We are working to develop and test a mobility aid for blind persons based on echolocation — the same principle of biological sonar that bats and dolphins use to navigate their environments. The project is inspired not only by other echolocating animals in nature, but by echolocation in blind persons themselves, some of whom have developed the ability to produce “clicks” with their tongues and interpret the reflected echoes to perceive their surroundings. We aim to investigate echolocation in a way that lowers its barrier to entry by “outsourcing” the echolocation to an artificial system. A field-testable prototype is currently near completion in our laboratory. User tests with blind research participants will soon begin in a controlled environment, CSAIL's "Holodeck" facility. In related neuroscience research, we also intend to measure changes in brain signals elicited by the artificial echoes in trained compared to untrained users. Taken together, this project will provide a technical, behavioral, and neural basis for studying echolocation as a means of perceiving one’s environment.