NOTE: Available activities have hot links indicated by the color blue or purple. Activities that will be available soon are indicated by the color black.

As you enter this discovery path you see a Giant Head that has a sprial staircase leading up to its left ear. The Head is transparent so you can see everything inside and is so big that you can walk through it and explore what's inside – the Six Basic Qualities of Sound Perception and the Auditory Pathway.

To the right is another path that leads to the Auditory Illusions, Localization – 3D Sound Adventures, and Why Does It Sound Good or Bad? activities.

To continue your visit check out the following online activities:

The study of sound perception is called psychoacoustics. Any time you hear a sound, there are some amazing things that happen. For every sound your ear-brain system processes, you get information about:

Pitch: how low or high can you hear?

Loudness: how soft or loud can you hear?

Phase: are our brains sensitive to a sound's increase/decrease cycle?

Direction: is the first sound to reach our ears always the first one heard?

Distance: how can we tell if a sound is near or far away?

Timbre: does every sound contain multiple frequencies?

Can you imagine what it would be like to listen to TV or a movie with the sound turned off!? We use our ears and brains to process sound energy into a form that our mind interprets as sound, language, noise, or music.

Our Outer Ear: how is sound transformed so we can hear it?

Our Middle Ear: how is sound transformed so we can hear it?

Our Inner Ear: how is sound transformed so we can hear it?

Sound illusions are interesting not only because they are so cool, but because they help solve the mysteries of how the human mind works. Since everyone hears these lllusions differently, scientists have to work even harder to create coherent theories about how the ear-brain system works.

Scale Illusion: do you hear a smooth or jagged melody?

Pitch Streaming: what happens when the pattern speeds up?

Octave Illusion: in which ear do you hear the high and low tones?

Shepard's Tones: why do these tones always go up in pitch?

Did you know that your brain processes sound in 3D? That's right, a healthy brain is able to determine up/down, front/back, and left/right information about any sound. This process is called localization.

(08") Motorcycle: make sure you look both ways before crossing the Soundgarden paths!

(20") Sniffing Doggy: listen to Rolf, the Soundgarden dog, as she sniffs her way into your heart.

(32") Busy, Buzzing Bee: there are lots of busy, buzzy bees in the Soundgarden.

Phase: how does a sound's phase effect our ability to locate which direction sounds come from?

Precedence: do we always hear the first sound to reach our ears first?

Loudness: do louder sounds effect our ability to locate sounds?

In the 19th and early 20th centuries, science made so many stunning discoveries that it seemed science would be able to, eventually, provide the answers to every question and working theories for every phenomena, including human perception. In the past fifteen years, we have learned more about how the brain works than in all of the previous centuries. There is, however, a lot that we don't know about how we perceive sound.

(13") – Melody from Sudan, North Africa. – do parts of this sound lumpy, bumpy, skinny, wide, or pleasant?

(13") – Melody from Tibet, China – what terms or words would you use to describe how this sounds?

(09") – Melody from India – do parts or all of this sound good, bad, happy, sad, pleasant, or unpleasant?

Shock to the System: how does your Limbic System respond to sound?

Beat It!: what is it about combinations of sound that make some things enjoyable or unbearable!?