This is slightly more difficult. The ears are positioned on the side of the head, so right to left differentiation is easier than up and down. Right to left relies on the difference in amplitude or volume between the signals coming in each ear. The ability to differentiate between sounds from above and sounds from below relies primarily on the shape of the ear and the ear canal making it a bit more ambiguous. However, your brain already knows how to do this, so trust it.
If being able to distinguish right vs. left increases your echolocation "resolution" in the "X-axis" (or along the horizon) being able to distinguish up vs. down, will help you improve your resolution in the "Y-axis" (or vertically). Each one of these resolutions will become very important when we start getting better and are able to start being aware of the non-visual images that our brain is creating.
- To begin, in a quiet environment have a partner make a sound in front of your face, but slightly above it at about a 45-degree angle upward. Have them rub their fingers together gently to create a very quiet sound.
- Have them move their hand below your face, to about a 45-degree angle and make the same subtle sound. This will give you a frame of reference for echolocating to these two positions.
- Now have them hold up your hard flat object in these two locations. Use your click signal and learn to sense its direction the same way you sensed the direction of the sound they made with their hand. At this point, have them tell you which position it’s in. IE: "the object is in the upper position" (and click to calibrate to it) and then "the object is in the lower position" (again click to calibrate)
- The next obvious step is for them to randomly change the location of the object and have you distinguish the location by pointing up or down. It’s important that they confirm your answer so that you can learn when you make a mistake.
- If this exercise proves to be difficult, simply move the object closer to your face until it becomes apparent. From there you can gradually have your partner move it away as you become more comfortable.
The reason we start in such a controlled environment is to isolate variables and make the signal and response from the object as apparent as possible. If there are lots of other objects around or lots of noises in the background this will certainly make it a lot harder especially when you're just starting out.