Seeing with sound: The boy who echolocates

Here’s the first 10 minutes of a documentary called Extraordinary People: The Boy Who Sees Without Eyes. It’s about Ben Underwood, a blind teenager from Sacramento who uses echolocation

At the age of 2, Underwood was diagnosed with retinoblastoma, a rare form of cancer that that affects about one in 5 million children. One year later, his eyes were surgically removed, to prevent the tumour from spreading throught the optic nerve and into the brain.

Soon after his surgery, Underwood realized that he could use echoes to determine the positions of objects, and began to develop this “six sense.” His ability to echolocate is now so sophisticated that he can ride a bike, skateboard and play computer games.

Watch the rest of The Boy Who Sees Without Eyes on You Tube.


  1. #1 Homie Bear
    October 22, 2007

    I saw that guy on Oprah once. He’s really amazing. Kind of mind-blowing, really.

  2. #2 Ahcuah
    October 22, 2007

    . . . retinoblastoma, a rare form of cancer that that affects about one in 5 children.

    One in 5? Surely you left out some zeros here.

  3. #3 Josh Charles
    October 23, 2007

    When I first heard about this, I thought it was a hoax or urban myth. I guess not?

  4. #4 Amiya Sarkar
    October 23, 2007

    You didn’t mention the frequency of sound he emanates. Is it in the audible range? Interference (noise) is more likely at 20Hz to 20kHz frequencies.

  5. #5 Mo
    October 23, 2007

    Ahcuah – yeah…all six!

    Amiya – I read somewhere that he emits 2 audible clicks per second.

  6. #6 Pete Martin
    October 24, 2007

    about 1 minute 2 in…

    How exactly does one echolocate onto a screen of a Nintendo DS?

  7. #7 dizzle
    October 24, 2007

    When he plays video games he is using sound cues from the games, not echolocation. The clicks emits are just tongue clicks and sound similar to dolphin clicks. They are easy to mimic.

    I’ve seen the entire documentary and it’s very interesting. They even do research to find out exactly what the limits are of his echolocation by having him attempt to identify different objects.

    Thinner objects are more difficult for him to locate of course. Round objects are also more problematic because they echo sounds back in a more dispersed pattern.

    A large portion is also dedicated to his over reliance on echolocation. He refuses to carry a cane because he feels that it is a symbol of disability.

  8. #8 pyko
    October 24, 2007

    wow, that is just amazing! We learnt in psychology that sometimes if you lose an important sense other senses become stronger than normal – though I guess this is an extreme case!

    and it is 6 in a million children that get retinoblastoma.

    hmm, but yes, i wonder how he plays the DS?

  9. #9 Nestor
    November 1, 2007

    Hm, looks like the video was removed – I’d heard of this kid, was looking forward to seeing him in action

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