Tags: Echolocation, Mobility, O&M
Bats, whales and other animals create sounds that bounce off objects to learn information about their environments. This strategy, called echolocation, helps them find prey and navigate under deep ocean depths and dark nighttime skies. Echolocation is now currently being researched as a tool for people with vision loss to also learn about the details of their surroundings.
Echolocation is the act of emitting a sound that bounces off an object or surface and comes back to you as an echo. This echo can help determine distance, location, motion, size, shape or surface material. There are two types of echolocation: passive and active.
Passive echolocation is sound that occur incidentally in the environment. As a car travels through a tunnel, the sound changes as the car enters the tunnel, travels through it and exits the tunnel. The sound your cane makes on the ground as you tap or roll will be different when you are next to a building compared to in an open area without obstruction.
Active echolocation, on the other hand, is sound you consciously produce like clapping your hands or clicking your tongue. Eventually, the sound you create bounces off other objects and comes back to you. Since your brain is familiar with the sounds you make, the echoes are easier for you to distinguish. By consistently emitting a sound and waiting for the sound to change, you can use active echolocation to help you navigate through an environment.
Echolocation is not a superhuman activity. You can begin to use it by just paying attention to the sounds you hear. How does the sound of your footsteps change as you travel from a tile floor to carpet? Listen to the sound your voice makes when you are in a small room compared to a large room. As you’re sitting in a moving car traveling down a residential road with parallel parked cars, roll your window down. Listen for the sound fluctuation between each parked car as you drive passed. Try to determine if there are lots of parked cars or just a few. For more of a challenge, practice this same technique walking by the cars or even trying to determine when you’re in front of a house versus in between them. These activities are helpful in heightening your auditory sensitization, a prerequisite for actively echo locating.
If you would like to practice active echolocation techniques, here are a few to try. Activities like these are a helpful first step in eventually being able to hear doorways or identifying how close you are to a wall. Mastering these activities is also a precursor to a slew of other skills that can be learned to efficiently use echolocation. To experience the full benefit of these activities, they should be performed blindfolded.
Hold a large, flat object like a magazine or a plate within arm’s reach from your face. Begin to produce a constant “shh” noise. As you slowly move the object closer and farther away from your face, you will hear a noticeable change in the pitch of the “shh” noise. You can also try using different objects like a soft pillow or a bowl to see how the material of the object changes the pitch and/or echo.
Try standing in front of a wall performing the same “shh” sound. Are you able to determine the distance from you to the wall?
Try standing in front of a doorway. As you side step from the open doorway to the wall beside the door, how does the echo sound change?
Echolocation skills take time, practice, and preferably, someone who is familiar with how to teach its methods. However, practicing the above strategies involved with passive and active echolocation can help hone your auditory senses and provide some of the benefits of echolocation in your travels.
Siobhan is both a Certified Orientation and Mobility Specialist and a Certified Vision Rehabilitation Therapist at Second Sense.
Even though I am fortunate enough to still have a substantial amount of vision, I do find it helpful to be aware of the sounds around me. When I am walking on a city sidewalk or at an intersection, I am able to hear the sounds of traffic around me, even with ear buds playing a book to me. Sometimes these sounds alert me to traffic I can’t yet see. I realize this is not ecolocation, but it is using sound to help me travel safely.
David, that’s a perfect example of why auditory skills are so important in orientation and mobility. As an O&M specialist, I like to say that I’m helping my clients add tools to their toolbox, so regardless of visual acuity, strong auditory skills are a must-have tool. Thanks for sharing!