Sine-wave Speech
Has your brain learned to understand Alien?
Play the alien sound first and see if you can guess what they're saying!
Now try these.
What's going on?
The 'alien voice' is actually 'degraded speech' - sound that has been changed on a computer by researchers to make it very difficult to understand.
Once your brain has heard the words, it can 'hear' them in the 'alien' speech.
Did you find you got better at hearing the words in the 'alien' speech?
Scientists call this 'pop out'.