Teach yourself to echolocate (2018)

Here's an idea, use a (portable) ultrasound emitter device that sends a pulse every set second and use an earpiece receiver that produces equivalent acoustics in audible range. The setup may reduce "tongue-fatigue' and the ultrasound will travel farther and can reflect off smaller objects. Would be an interesting experiment if nothing else.

I suspect it would be a very challenging problem for the earpiece part to recreate the directional info as well as our own ears, since the brain's ability to detect the direction of sounds depends on the shape of the ear itself.

Maybe a simple mechanical clicker device like those used for dog training could be a useful tool.