This demonstration lets you listen to a couple of well known ambiguous audio samples. One can be heard as either 'Green Needle' or 'Brainstorm'. The other sounds like either 'Yanny' or 'Laurel'. If you can only hear a sample one way, this demonstration allows you to distort the sample to only hear some of its frequencies. The frequencies that you hear will be the ones in green between the two slider handles. For me, I find it easier to hear 'Laurel' and 'Brainstorm' when I restrict the sample to only its low frequencies - those between, say, 1 Hz and 1200 Hz. I find it easier to hear 'Yanny' and 'Green Needle' when I hear only high frequencies, such as those between 3000 Hz and 15000 Hz. Some things to try:

• Can you make yourself hear the sound either way, or does your ear&brain hear what they want?
• If you first listen to a sample with only the low frequencies, do you then hear a different sound when you listen with all frequencies included, compared to when you first listen to the sample with only high frequencies? What does that suggest about how people perceive ambiguous stimuli?
• Look at the word 'Brainstorm' when you listen to the full brainstorm/greenNeedle sample with no frequency restrictions. Are you more likely to hear the sample as 'Brainstorm'? Now try looking at 'Green Needle'. What does that suggest about the ability of visual inputs to affect your listening experience? For another example of cross-modal perceptual effects , see the McGurk Effect.
• When you press the 'Palate Cleanser' button, you will hear the sample played before 'Brainstorm' in the original toy (listen at 6:30). I find it easier to switch between hearing 'Brainstorm' and 'Green Needle' when I first press this button. Why might that be?

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