If you are comfortable discerning a relatively large object in front of you, such as a car, you should attempt circumnavigation. This will help you orient, and re-orient yourself to the object as you circle around it. Try to locate yourself a relatively safe distance from it. Something on the order of 4 - 10 feet away. Now simply walk around it, keeping it in your "echolocation scope" at all times.
Try to keep your distance the same. If you start getting to close it should be clearly louder, but if you start moving further away from it, it can be very hard to tell until you have lost sight of it altogether.
Also, see if you can navigate 360 degrees around it and end up right back where you started. Keep in mind that if there are flat objects on the object you can use those to identify your orientation with respect to the object, however, if there are flat surfaces, that also means that they will be at an angle to you at some point so the response from the object will seem to fade when you are in particular orientations. Learn to judge the distance to the object with that in mind.