[faceplanted]

Would it be possible to have headphones, bone conduction or otherwise, something they can still hear normal sounds through at least, which could convert an ultrasound "click" played by a speaker into a human audible "click" so they could use this in place of the audible clicking of human echolocation?

So a high frequency speaker on their head plays the sound, and the headphones convert the returning reflected sound in the correct frequency range into a lower frequency and the brain does the rest. Seem like if we can have active noise cancelling headphones removing sound frequencies, we can have a headphone with microphones converting a frequency.

[marco_trujillo]

Brilliant idea. Daniel Kish has a patent on a similar device that clicks at an audible frequency, you can adjust the clicking rate, power and pitch (different pitch provides different information).