I'm not an echolocater. I've never tried it. But yesterday in the grocery store I could tell I was in the paper towel aisle because the paper towels were so quiet. They absorb more of the ambient sound than canned vegetables.

Airport concourses have tiled floors but the floors in some airport gates are carpeted. The carpet absorbs ambient sounds and the gate sounds quieter than the concourse.

These aren't things I use to navigate. I don't actively look for them, I just can't help but notice them. What if someone actually tried to notice?

Echolocation is a skill most people could learn. We tune out most of the ambient noise we hear to focus on whatever we're listening to, but if we focused on listening to our surroundings we wouldn't tune it out. We'd start noticing tiny differences we could interpret to know what's around us. If you stood in a grocery store aisle with paper towels on one side and canned goods on the other and clicked your tongue you'd notice the difference. With practice I believe you could stand in a grocery store aisle that had canned goods on both sides, click your tongue, and be able to tell which side you were closest to.

I use click based echo location on my college campus. It takes a lot of practice, but basically I’m listening for reflected sound‘s. I take into account the delay between the click and the reflection, the direction it comes from, and the frequencies I get back. It will sound slightly different depending on what it bounces off of. I am not sure how easy a skill it is to be taught. I picked it up through trial and error

First don't be sorry about using the word see :) or seen, (BTW it should be saw,) I don't use echo location although I was trained by Daniel Kish for a day buy I'll try to explain how it works.

when people click/clap/make a sound, sound bounces off of an object, depending on what object that is, the sound can come back to the persons ear sounding diffirent, a wall for example will sound flat but full, were as a gate might sound open with a hint of flatness for the rales on the gate if it's one of those types.

The key is paying attention, LOTS of attention, to how things sound. I have played with it a little, but don't actually use it (I am sighted, but I don't know any of my blind clients who use it either). For example, I can keep myself centered walking down a pitch-black hallway by using echolocation, but I can't detect obstacles or be sure about doorways.

I guess a good starting point to is is in an empty gymnasium - large room, hard acoustically reflective surfaces. Stand five feet away from a wall and sharply click with your tongue/mouth. Slowly spin in a circle while clicking and you can hear the difference between facing the open room and facing the wall. Once you know where the wall is, slowly walk towards the wall while clicking. You should be able to tell when you are very close before hitting the wall.

A room with carpet sounds different than a room with tile floor. A room with wooden walls sounds different than a room with drywall. Furniture like a couch or a recliner absorb sound whereas something like a table reflects it. A big part of echolocating is paying lots of attention to these little variations. We tend to be subconsciously aware of these things - we can tell automatically if we are in a large space or a small one by the sound, but we tend to not pay attention to the background.

I wish I knew too. I teach Orientation and Mobility and I have a few students who seem to use echolocation intuitively but not functionally. I wish I could teach them how to harness the powers but it seems a bit complicated. Daniel Kish, you probably came across him, is the "real life Batman", educating people on this method. In my teaching program, we were advised to not get into that because clicking isn't socially acceptable. I say who gives a heck if it works but it's quite the science. I believe I read once that Daniel says the click has to be pretty particular to be effective.

Here's a link to $1 where you can order his textbook on understanding and using echolocation. I'm totally going to dive into it one day and see if I can incorporate it into teaching. Let me know how it goes for you!

What I've heard is that this technique only works amazingly well if you're starting as early as possible, basically as a toddler.

In general I'm quite annoyed at how everyone seems to think we're all amazing at hearing things. Don't let such absurd expectations pressure you!