Batman is all about advancing technology through his super-cool gadgetry, so it’s no surprise that he adapted a highly useful remote sensing technique from his namesake animal.
SONAR = SOund Navigation And Ranging
The physical principles behind echolocation have been adapted into sonar technology used in submarines to detect other subs and whatever else is in the water. Considering that echolocation in animals was theorized more than a century before the invention of sonar, it's likely that there was a certain amount of bioinspiration involved. It was also used to sense objects in the air before radar was developed. Radar is a generally superior remote sensing system because radio waves move faster than sound waves, but sonar still remains in use underwater because the radar's emitted microwaves are rapidly absorbed by water.
Passive sonar was the first system employed in underwater detection, and it worked by listening in on well-placed hydrophones. It’s called passive because the hydrophones are only receiving sounds made by other things without producing any sounds themselves. It was a subpar arrangement since it depended on a quiet ocean while you hoped that what you were looking for was noisy, which might not always be the case. World War II compelled developers to raise the level of the technology and gave us active sonar. Now subs were sending out their own *pings* (the ones you’ve surely heard in Das Boot or The Hunt for Red October) and using the echoes in a manner closer to bats. The technology is also used frequently today to map the ocean floor through multibeam swath bathymetry.
Daniel Kish is also featured in the video, and another person rendered blind by retinal cancer who has learned to use echolocation instead of a cane. He is president of World Access for the Blind and teaches children how to navigate an unfamiliar environment using sound.
Cool connection to the comic book world: another blind echolocator, Juan Ruiz, appeared in the first episode of Stan Lee’s Superhumans where he demonstrated his super abilities to navigate and measure the length of a cave. It’s an excellent show for investigating the possibilities of superpowers in our mortal realm!
Now, comic book fans, another superhero may be coming to mind: